Check an Armstrong number is or not?

class Program

    {

        static void Main(string[] args)

        {

            int sum = 0, i, r;

            Console.WriteLine("Enter the number");

            int n = int.Parse(Console.ReadLine());

            for (i = n; i > 0; i = i / 10)

            {

                r = i % 10;

                sum = sum + r * r * r;

            }

            if (n == sum)

            {

                Console.WriteLine("This is Armstrong number");

            }

            else

            {

                Console.WriteLine("This is not Armstrong number");

            }

            Console.WriteLine();

            Console.ReadLine();

        }

    }

OUTPUT:

Enter the number: 153
This is Armstrong number