finite good numbers is not divisible by $k$
Source: 2012 China TST - Quiz 1 - Day 2 - P5
March 15, 2012
number theory proposednumber theory
Problem Statement
For a positive integer , denote by the number of its positive divisors. For a positive integer , if for all , we call a good number. Prove that for any positive integer , there are only finitely many good numbers not divisible by .