Find the lowest integer N whose factorials' digits' sum is X

factorial.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Numerics;

namespace Lowest_Value_For_Given_Sum
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                uint sum, max;

                Console.WriteLine(Environment.NewLine + "Enter max n factorial value to try (n!).");
                Console.Write(" >");

                string userMax = Console.ReadLine();

                Console.WriteLine("Enter sum to find.");
                Console.Write(" >");

                string userSum = Console.ReadLine();
                if (uint.TryParse(userSum, out sum) && uint.TryParse(userMax, out max))
                {
                    bool found = false;

                    for (uint i = 1; i <= max; i++)
                    {
                        BigInteger f = Factorial(i);
                        double s = SumOfDigits(f);
                        Console.WriteLine(i.ToString() + "! = " + f.ToString() + " | Sum: " + s.ToString());
                        if (sum == s)
                        {
                            Console.WriteLine("found! n: " + i.ToString());
                            found = true;
                            break;
                        }
                    }

                    if (!found)
                        Console.WriteLine("couldnt find " + sum.ToString() + " in range 1-" + max.ToString());
                }
            }
        }

        private static BigInteger Factorial(uint number)
        {
            if (number <= 1)
                return number;
            else
                return number * Factorial(number - 1);
        }

        private static ulong SumOfDigits(BigInteger number)
        {
            ulong sum = 0;
            while (number != 0)
            {
                sum += (ulong)(number % 10);
                number /= 10;
            }
            return sum;
        }
    }
}