90

This number is a composite.

Just showing those entries submitted by 'Moser': (Click here to show all)

There are only 8 positive integers n for which the number of primes ≤ n (pi(n)) equals the number of positive integers ≤ n relative prime to n (phi(n)). They are 2, 3, 4, 8, 10, 14, 20, and 90. [Moser]