If we let \(f(n)\) denote the sum of all the positive divisors of the integer \(n \) , how many integers \(i \) exist such that \(1 \le i \le 2010\) and \(f(i) = 1 + \sqrt{i} + i\)?
I have no idea how to start on this problem
There are 20 integers $i$ that work.
