Easy

Quiz

#507 Perfect Number

APPROACH

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

1 of 4

What is the optimal approach for this problem?