507.Perfect-Number.js

// A perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. A divisor of an integer x is an integer that can divide x evenly.
// Given an integer n, return true if n is a perfect number, otherwise return false.

/**
 * @param {number} num
 * @return {boolean}
 */
var checkPerfectNumber = function(num) {
    if (num == 1) return false;
    let s = 1;
    for (let i = 2; i <= Math.sqrt(num); i++) {
        if (num % i == 0) {
            s += i;
            s += num / i;
        }
    }
    return num == s ? true : false;
};