507.cpp

class Solution {
public:
    bool checkPerfectNumber(int num) {
        int result = 1;
        for(int i = 2; i < sqrt(num); i++) {
            if (num%i == 0) {
                //cout << result << ", " << i << endl;
                result += i + num/i;
            }
        }
        return result == num && num != 1 ? true: false;
    }
};