NarcissisticNumberChecker.cs

using System;

namespace Algorithms.Numeric
{
    /// <summary>
    ///     A Narcissistic number is equal to the sum of the cubes of its digits. For example, 370 is a
    ///     Narcissistic number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
    /// </summary>
    public static class NarcissisticNumberChecker
    {
        /// <summary>
        ///     Checks if a number is a Narcissistic number or not.
        /// </summary>
        /// <param name="number">Number to check.</param>
        /// <returns>True if is a Narcissistic number; False otherwise.</returns>
        public static bool IsNarcissistic(int number)
        {
            var sum = 0;
            var temp = number;
            var numberOfDigits = 0;
            while (temp != 0)
            {
                numberOfDigits++;
                temp /= 10;
            }

            temp = number;
            while (number > 0)
            {
                var remainder = number % 10;
                var power = (int)Math.Pow(remainder, numberOfDigits);

                sum += power;
                number /= 10;
            }

            return sum == temp;
        }
    }
}