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C++ Program to check a number is a perfect number or not


In this program, You will learn how to check a number is a perfect number or not in C++.


Some list are: 6, 28, 496, 8128

if (n % i == 0) {

   s = s + i; 
}

Example: How to check a number is a perfect number or not in C++

#include<iostream>
using namespace std;

int main() {
    int n, i = 1, s = 0;
    cout << "Enter a number:";
    cin>>n;

    while (i < n) {
        if (n % i == 0) {
            s = s + i;
        }
        i++;
    }

    if (s == n) {
        cout << "This is a perfect number:" << n;
    } else {
        cout << "This is not a perfect number :" << n;
    }

    return 0;
}

Output:

Enter a number:6
This is a perfect number:6