Find the largest positive integer n such that n \varphi(n) is a perfect square. (\varphi(n) is the number of integers k, 1 \leq k \leq n that are relatively prime to n)
Find the largest positive integer n such that n \varphi(n) is a perfect square. (\varphi(n) is the number of integers k, 1 \leq k \leq n that are relatively prime to n)