Problem B. 4651. (October 2014)
B. 4651. A positive integer \(\displaystyle n\) is said to be exotic if it is divisible by the number of its positive factors. Prove the following statements:
\(\displaystyle a)\) If an exotic number is odd then it is a perfect square.
\(\displaystyle b)\) There are infinitely many exotic numbers.
(3 pont)
Deadline expired on 10 November 2014.
Statistics:
264 students sent a solution.  
3 points:  197 students. 
2 points:  55 students. 
1 point:  6 students. 
0 point:  4 students. 
Unfair, not evaluated:  2 solutions. 
