Maximum number of distinct prime factors of numbers below $2^{64}$












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What is the maximum number of distinct prime factors of numbers below $2^{64}$? I'm interested in the exact count, not just an estimate.



In other words, what is the largest $omega(n)$, where $n < 2^{64}$?










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    0












    $begingroup$


    What is the maximum number of distinct prime factors of numbers below $2^{64}$? I'm interested in the exact count, not just an estimate.



    In other words, what is the largest $omega(n)$, where $n < 2^{64}$?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      What is the maximum number of distinct prime factors of numbers below $2^{64}$? I'm interested in the exact count, not just an estimate.



      In other words, what is the largest $omega(n)$, where $n < 2^{64}$?










      share|cite|improve this question









      $endgroup$




      What is the maximum number of distinct prime factors of numbers below $2^{64}$? I'm interested in the exact count, not just an estimate.



      In other words, what is the largest $omega(n)$, where $n < 2^{64}$?







      number-theory prime-numbers prime-factorization






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 19 '18 at 9:18









      Ecir HanaEcir Hana

      417414




      417414






















          1 Answer
          1






          active

          oldest

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          5












          $begingroup$

          The number with the most distinct prime factors will have the form



          $$2cdot 3cdot 5cdot 7cdots$$



          So all you need is to multiply all primes until you reach $2^{64}$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            It's 15, in case anyone's wondering... Thanks!
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:26










          • $begingroup$
            How did you get 15 @EcirHana ?
            $endgroup$
            – rsadhvika
            Dec 19 '18 at 9:36










          • $begingroup$
            @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:45












          • $begingroup$
            @EcirHana Is that a typo?
            $endgroup$
            – Szeto
            Dec 19 '18 at 9:47










          • $begingroup$
            @Szeto Sorry, what is a typo?
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:48











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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          5












          $begingroup$

          The number with the most distinct prime factors will have the form



          $$2cdot 3cdot 5cdot 7cdots$$



          So all you need is to multiply all primes until you reach $2^{64}$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            It's 15, in case anyone's wondering... Thanks!
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:26










          • $begingroup$
            How did you get 15 @EcirHana ?
            $endgroup$
            – rsadhvika
            Dec 19 '18 at 9:36










          • $begingroup$
            @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:45












          • $begingroup$
            @EcirHana Is that a typo?
            $endgroup$
            – Szeto
            Dec 19 '18 at 9:47










          • $begingroup$
            @Szeto Sorry, what is a typo?
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:48
















          5












          $begingroup$

          The number with the most distinct prime factors will have the form



          $$2cdot 3cdot 5cdot 7cdots$$



          So all you need is to multiply all primes until you reach $2^{64}$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            It's 15, in case anyone's wondering... Thanks!
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:26










          • $begingroup$
            How did you get 15 @EcirHana ?
            $endgroup$
            – rsadhvika
            Dec 19 '18 at 9:36










          • $begingroup$
            @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:45












          • $begingroup$
            @EcirHana Is that a typo?
            $endgroup$
            – Szeto
            Dec 19 '18 at 9:47










          • $begingroup$
            @Szeto Sorry, what is a typo?
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:48














          5












          5








          5





          $begingroup$

          The number with the most distinct prime factors will have the form



          $$2cdot 3cdot 5cdot 7cdots$$



          So all you need is to multiply all primes until you reach $2^{64}$.






          share|cite|improve this answer









          $endgroup$



          The number with the most distinct prime factors will have the form



          $$2cdot 3cdot 5cdot 7cdots$$



          So all you need is to multiply all primes until you reach $2^{64}$.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Dec 19 '18 at 9:20









          5xum5xum

          91.3k394161




          91.3k394161












          • $begingroup$
            It's 15, in case anyone's wondering... Thanks!
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:26










          • $begingroup$
            How did you get 15 @EcirHana ?
            $endgroup$
            – rsadhvika
            Dec 19 '18 at 9:36










          • $begingroup$
            @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:45












          • $begingroup$
            @EcirHana Is that a typo?
            $endgroup$
            – Szeto
            Dec 19 '18 at 9:47










          • $begingroup$
            @Szeto Sorry, what is a typo?
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:48


















          • $begingroup$
            It's 15, in case anyone's wondering... Thanks!
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:26










          • $begingroup$
            How did you get 15 @EcirHana ?
            $endgroup$
            – rsadhvika
            Dec 19 '18 at 9:36










          • $begingroup$
            @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:45












          • $begingroup$
            @EcirHana Is that a typo?
            $endgroup$
            – Szeto
            Dec 19 '18 at 9:47










          • $begingroup$
            @Szeto Sorry, what is a typo?
            $endgroup$
            – Ecir Hana
            Dec 19 '18 at 9:48
















          $begingroup$
          It's 15, in case anyone's wondering... Thanks!
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:26




          $begingroup$
          It's 15, in case anyone's wondering... Thanks!
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:26












          $begingroup$
          How did you get 15 @EcirHana ?
          $endgroup$
          – rsadhvika
          Dec 19 '18 at 9:36




          $begingroup$
          How did you get 15 @EcirHana ?
          $endgroup$
          – rsadhvika
          Dec 19 '18 at 9:36












          $begingroup$
          @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:45






          $begingroup$
          @rsadhvika the product of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 is 614889782588491410, which is less than 614889782588491410 ($2^{64}$). Including 53 it is 32589158477190044730.
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:45














          $begingroup$
          @EcirHana Is that a typo?
          $endgroup$
          – Szeto
          Dec 19 '18 at 9:47




          $begingroup$
          @EcirHana Is that a typo?
          $endgroup$
          – Szeto
          Dec 19 '18 at 9:47












          $begingroup$
          @Szeto Sorry, what is a typo?
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:48




          $begingroup$
          @Szeto Sorry, what is a typo?
          $endgroup$
          – Ecir Hana
          Dec 19 '18 at 9:48


















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