507. Perfect Number

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.

 

Example 1:

Input: num = 28
Output: true
Explanation: 28 = 1 + 2 + 4 + 7 + 14
1, 2, 4, 7, and 14 are all divisors of 28.

Example 2:

Input: num = 7
Output: false

 

Constraints:

• 1 <= num <= 108

 Solution:

In JS:

var checkPerfectNumber = function(num) {

    let sumOfDiv = 0;

    for(let index = 1; index < num; index++){

      if(num%index == 0) sumOfDiv += index;

    }

    if(sumOfDiv == num) return true;

    else return false;

};