1. Sum OF Given number c#.

2. Reverse  a number c#.

3. Count 1 in given number c#.

string getnumber = "";
            int sum = 0;
            Console.Write("Enter No :");
            getnumber = Console.ReadLine();
            int one = 0;
            for (int i = 0; i < getnumber.Length; i++)
            {
                string s = getnumber[i].ToString();
                if (s == "1")
                {
                    one++;
                }
                sum = sum + Convert.ToInt32(s);
            }

            Console.WriteLine("Sum Of Digits Of No :"+sum);
            Console.WriteLine("No of One :" + one);
            Console.Write("Reverse No.");
            for (int i = getnumber.Length - 1; i >= 0; i--)
            {
                Console.Write(getnumber[i]);
            }