C++ Program to Check Armstrong Number

In this program, you'll learn to find number is Armstrong number or not.

Armstrong number is a number that is equal to the sum of cubes of its digits. For example 0, 1, 153, 370, 371 and 407 are the Armstrong numbers.

Let's try to understand why 153 is an Armstrong number.

153 = (1*1*1)+(5*5*5)+(3*3*3)
= 1 + 125 + 27
= 153

Source Code

#include <iostream>
using namespace std;
int main()
{
    int num, r, sum = 0, temp;
    cout<<"Enter any number: ";
    cin>>num;
    temp = num;

    while (temp > 0)
    {
        r = temp % 10;
        sum = sum + (r * r * r);
        temp = temp / 10;
    }
    if (num == sum)
        cout<<"Armstrong Number";
    else
        cout<<"Not an Armstrong Number";
    return 0;
}

Output

Enter any number: 153
Armstrong Number