Find all values of $n$ such that $varphi(n) = n/6$. [duplicate]












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  • Is there $phi(n)=n/6$

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Using the product formula (the formula with the prime factors of $n$), I got
$$1=6frac{(P_1-1)}{P_1}frac{(P_2-1)}{P_2}cdotsfrac{(P_k-1)}{P_k},.$$










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marked as duplicate by Shailesh, Leucippus, Brahadeesh, Dietrich Burde number-theory
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Dec 12 '18 at 9:32


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.














  • 2




    $begingroup$
    Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
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    – platty
    Dec 12 '18 at 0:19
















0












$begingroup$



This question already has an answer here:




  • Is there $phi(n)=n/6$

    2 answers




Using the product formula (the formula with the prime factors of $n$), I got
$$1=6frac{(P_1-1)}{P_1}frac{(P_2-1)}{P_2}cdotsfrac{(P_k-1)}{P_k},.$$










share|cite|improve this question











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marked as duplicate by Shailesh, Leucippus, Brahadeesh, Dietrich Burde number-theory
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Dec 12 '18 at 9:32


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.














  • 2




    $begingroup$
    Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
    $endgroup$
    – platty
    Dec 12 '18 at 0:19














0












0








0





$begingroup$



This question already has an answer here:




  • Is there $phi(n)=n/6$

    2 answers




Using the product formula (the formula with the prime factors of $n$), I got
$$1=6frac{(P_1-1)}{P_1}frac{(P_2-1)}{P_2}cdotsfrac{(P_k-1)}{P_k},.$$










share|cite|improve this question











$endgroup$





This question already has an answer here:




  • Is there $phi(n)=n/6$

    2 answers




Using the product formula (the formula with the prime factors of $n$), I got
$$1=6frac{(P_1-1)}{P_1}frac{(P_2-1)}{P_2}cdotsfrac{(P_k-1)}{P_k},.$$





This question already has an answer here:




  • Is there $phi(n)=n/6$

    2 answers








number-theory elementary-number-theory prime-numbers diophantine-equations totient-function






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edited Dec 12 '18 at 3:28









Batominovski

1




1










asked Dec 12 '18 at 0:14









MeganMegan

32




32




marked as duplicate by Shailesh, Leucippus, Brahadeesh, Dietrich Burde number-theory
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Dec 12 '18 at 9:32


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.









marked as duplicate by Shailesh, Leucippus, Brahadeesh, Dietrich Burde number-theory
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Dec 12 '18 at 9:32


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.










  • 2




    $begingroup$
    Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
    $endgroup$
    – platty
    Dec 12 '18 at 0:19














  • 2




    $begingroup$
    Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
    $endgroup$
    – platty
    Dec 12 '18 at 0:19








2




2




$begingroup$
Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
$endgroup$
– platty
Dec 12 '18 at 0:19




$begingroup$
Welcome to MSE! For some basic information about writing mathematics at this site see, e.g., here, here, here and here. Additionally, if you are looking for prsomebody to check your proof, please update your post to include the tag proof-verification.
$endgroup$
– platty
Dec 12 '18 at 0:19










2 Answers
2






active

oldest

votes


















0












$begingroup$

i don't think the proof is enough, as it stands. There is a small ingredient. We are taking the product, with one or more primes, of $frac{p-1}{p}.$



There are two types of potential problems. Some cancellation is possible, putting the product in lowest terms may be a bit surprising. Second, we can get the product arbitrarily close to $frac{1}{6}$ byt choosing many large primes.



However: the collection of chosen primes is finite, and one of them is largest, call that $q.$ For any of the other, smaller primes, since $p<q,$ we also have $p-1 < q.$ That means that the numerator of the product fraction is not divisible by $q.$ When we put the fraction in lowest terms, the denominator is still divisible by $q.$



For your problem, this means that the largest prime involved, $q,$ must be a factor of $6.$ The possibilities for the product are just:
$$ { }, frac{1}{1} $$
$$ { 2}, frac{1}{2} $$
$$ { 3}, frac{2}{3} $$
$$ { 2,3}, frac{1}{3} $$






share|cite|improve this answer









$endgroup$





















    -1












    $begingroup$

    Hints:



    We know that if $;p_1,...,p_k;$ are the different primes diving $;n;$ , then



    $$varphi(n)=nprod_{j=1}^kleft(1-frac1{p_j}right)$$



    Well, take it now...And I couldn't completely understand what you wrote, but I think you're on the right track: there is no solution.






    share|cite|improve this answer









    $endgroup$













    • $begingroup$
      i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
      $endgroup$
      – Megan
      Dec 12 '18 at 0:27


















    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0












    $begingroup$

    i don't think the proof is enough, as it stands. There is a small ingredient. We are taking the product, with one or more primes, of $frac{p-1}{p}.$



    There are two types of potential problems. Some cancellation is possible, putting the product in lowest terms may be a bit surprising. Second, we can get the product arbitrarily close to $frac{1}{6}$ byt choosing many large primes.



    However: the collection of chosen primes is finite, and one of them is largest, call that $q.$ For any of the other, smaller primes, since $p<q,$ we also have $p-1 < q.$ That means that the numerator of the product fraction is not divisible by $q.$ When we put the fraction in lowest terms, the denominator is still divisible by $q.$



    For your problem, this means that the largest prime involved, $q,$ must be a factor of $6.$ The possibilities for the product are just:
    $$ { }, frac{1}{1} $$
    $$ { 2}, frac{1}{2} $$
    $$ { 3}, frac{2}{3} $$
    $$ { 2,3}, frac{1}{3} $$






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      i don't think the proof is enough, as it stands. There is a small ingredient. We are taking the product, with one or more primes, of $frac{p-1}{p}.$



      There are two types of potential problems. Some cancellation is possible, putting the product in lowest terms may be a bit surprising. Second, we can get the product arbitrarily close to $frac{1}{6}$ byt choosing many large primes.



      However: the collection of chosen primes is finite, and one of them is largest, call that $q.$ For any of the other, smaller primes, since $p<q,$ we also have $p-1 < q.$ That means that the numerator of the product fraction is not divisible by $q.$ When we put the fraction in lowest terms, the denominator is still divisible by $q.$



      For your problem, this means that the largest prime involved, $q,$ must be a factor of $6.$ The possibilities for the product are just:
      $$ { }, frac{1}{1} $$
      $$ { 2}, frac{1}{2} $$
      $$ { 3}, frac{2}{3} $$
      $$ { 2,3}, frac{1}{3} $$






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        i don't think the proof is enough, as it stands. There is a small ingredient. We are taking the product, with one or more primes, of $frac{p-1}{p}.$



        There are two types of potential problems. Some cancellation is possible, putting the product in lowest terms may be a bit surprising. Second, we can get the product arbitrarily close to $frac{1}{6}$ byt choosing many large primes.



        However: the collection of chosen primes is finite, and one of them is largest, call that $q.$ For any of the other, smaller primes, since $p<q,$ we also have $p-1 < q.$ That means that the numerator of the product fraction is not divisible by $q.$ When we put the fraction in lowest terms, the denominator is still divisible by $q.$



        For your problem, this means that the largest prime involved, $q,$ must be a factor of $6.$ The possibilities for the product are just:
        $$ { }, frac{1}{1} $$
        $$ { 2}, frac{1}{2} $$
        $$ { 3}, frac{2}{3} $$
        $$ { 2,3}, frac{1}{3} $$






        share|cite|improve this answer









        $endgroup$



        i don't think the proof is enough, as it stands. There is a small ingredient. We are taking the product, with one or more primes, of $frac{p-1}{p}.$



        There are two types of potential problems. Some cancellation is possible, putting the product in lowest terms may be a bit surprising. Second, we can get the product arbitrarily close to $frac{1}{6}$ byt choosing many large primes.



        However: the collection of chosen primes is finite, and one of them is largest, call that $q.$ For any of the other, smaller primes, since $p<q,$ we also have $p-1 < q.$ That means that the numerator of the product fraction is not divisible by $q.$ When we put the fraction in lowest terms, the denominator is still divisible by $q.$



        For your problem, this means that the largest prime involved, $q,$ must be a factor of $6.$ The possibilities for the product are just:
        $$ { }, frac{1}{1} $$
        $$ { 2}, frac{1}{2} $$
        $$ { 3}, frac{2}{3} $$
        $$ { 2,3}, frac{1}{3} $$







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 12 '18 at 0:54









        Will JagyWill Jagy

        103k5101200




        103k5101200























            -1












            $begingroup$

            Hints:



            We know that if $;p_1,...,p_k;$ are the different primes diving $;n;$ , then



            $$varphi(n)=nprod_{j=1}^kleft(1-frac1{p_j}right)$$



            Well, take it now...And I couldn't completely understand what you wrote, but I think you're on the right track: there is no solution.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
              $endgroup$
              – Megan
              Dec 12 '18 at 0:27
















            -1












            $begingroup$

            Hints:



            We know that if $;p_1,...,p_k;$ are the different primes diving $;n;$ , then



            $$varphi(n)=nprod_{j=1}^kleft(1-frac1{p_j}right)$$



            Well, take it now...And I couldn't completely understand what you wrote, but I think you're on the right track: there is no solution.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
              $endgroup$
              – Megan
              Dec 12 '18 at 0:27














            -1












            -1








            -1





            $begingroup$

            Hints:



            We know that if $;p_1,...,p_k;$ are the different primes diving $;n;$ , then



            $$varphi(n)=nprod_{j=1}^kleft(1-frac1{p_j}right)$$



            Well, take it now...And I couldn't completely understand what you wrote, but I think you're on the right track: there is no solution.






            share|cite|improve this answer









            $endgroup$



            Hints:



            We know that if $;p_1,...,p_k;$ are the different primes diving $;n;$ , then



            $$varphi(n)=nprod_{j=1}^kleft(1-frac1{p_j}right)$$



            Well, take it now...And I couldn't completely understand what you wrote, but I think you're on the right track: there is no solution.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Dec 12 '18 at 0:23









            DonAntonioDonAntonio

            178k1493229




            178k1493229












            • $begingroup$
              i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
              $endgroup$
              – Megan
              Dec 12 '18 at 0:27


















            • $begingroup$
              i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
              $endgroup$
              – Megan
              Dec 12 '18 at 0:27
















            $begingroup$
            i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
            $endgroup$
            – Megan
            Dec 12 '18 at 0:27




            $begingroup$
            i used the same definition but because i couldnt type the product symbol i used the definition of the product....anyway thanks for verifying that there is no solution
            $endgroup$
            – Megan
            Dec 12 '18 at 0:27



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