Java program to check Armstrong number

Here’s a Java program to check whether a given number is an Armstrong number or not:

import java.util.Scanner;

public class ArmstrongNumber {
    public static void main(String[] args) {
        Scanner sc = new Scanner(;
        System.out.print("Enter a number: ");
        int num = sc.nextInt();

        int originalNum = num;
        int sum = 0;

        while (num != 0) {
            int digit = num % 10;
            sum += Math.pow(digit, 3);
            num /= 10;

        if (originalNum == sum) {
            System.out.println(originalNum + " is an Armstrong number");
        } else {
            System.out.println(originalNum + " is not an Armstrong number");

In this program, we first import the Scanner class from the java.util package to read input from the user.

We then prompt the user to enter a number using the System.out.print() function and read the input using the nextInt() function of the Scanner class.

Next, we declare three integer variables originalNum, sum, and digit. We initialize originalNum to the entered number and sum to 0.

We then use a while loop to calculate the sum of cubes of digits of the entered number and store the result in the sum variable.

Finally, we compare the original number with the calculated sum to determine whether it is an Armstrong number or not, and display the result using the System.out.println() function.

When you run this program and enter a number, the output will be:

Enter a number: 153
153 is an Armstrong number

If you enter a non-Armstrong number like 123, the output will be:

Enter a number: 123
123 is not an Armstrong number

This program is a basic example of how to check if a given number is an Armstrong number or not using Java.