Perfect Number

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself.

Now, given an integer n, write a function that returns true when it is a perfect number and false when it is not.

var checkPerfectNumber = function(n) {    var sum = 0;    if(n <= 0 || n == 1) {        return false    }    for(var i = 2; i <= Math.sqrt(n); i++) {        if(n % i == 0){            sum += i + n / i;        }    }    return (sum + 1) == n};