Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Number Theory

  1. Apr 10, 2008 #1
    Find eight different numbers n with phi(n) = 240.



    phi(n) = the number of positive integers less than or equal to n, that are relatively prime to n.
     
  2. jcsd
  3. Apr 10, 2008 #2

    HallsofIvy

    User Avatar
    Science Advisor

    Surely you are aware that you must show what you have tried yourself before anyone can give suggestions?
     
  4. Apr 10, 2008 #3
    12^12 = (3^12)(2^24)

    phi(12^12) = phi(3^12) * phi(2^24) = 2^(24-1) * (2-1) *3^12 *(3-1)
    = 2^23 * 3^12 * 2 = 2^24 * 3^12
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook