How to check whether a number is Armstrong number or not

import java.util.ArrayList;
import java.util.Scanner;

public class ArmstrongNumberUsingStream {

	public static void main(String args[]) {

		// To check whether a give number is Armstrong number or not
		Scanner inpInt = new Scanner(System.in);
		System.out.print("Enter a number to check for Armstrong or not=");
		int inpNum = inpInt.nextInt();
		System.out.println("The given number is=" + inpNum);
		String strVal = String.valueOf(inpNum);

		ArrayList<Integer> arrOfDigits = new ArrayList<Integer>();
		for (char ch : strVal.toCharArray())
			arrOfDigits.add(Character.getNumericValue(ch));
		System.out.println("The list of Digits are= " + arrOfDigits);

		// Applying map and reduce method to find our sum of cubes
		int sumOfCubes = arrOfDigits.stream().map(a -> a * a * a).reduce(0, (x, y) -> x + y);
		if (sumOfCubes == inpNum)
			System.out.println("The given number " + inpNum + " is an ArmstrongNumber");
		else
			System.out.println("The given number " + inpNum + " is not an ArmstrongNumber");
	}
}