What is the sum of the digits of the number 2^1000?

Question

This is a problem from Project Euler, and this question includes some source code, so consider this your spoiler alert, in case you are interested in solving it yourself. It

Answer 1

I used bitwise shifting to left. Then converting to array and summing its elements. My end result is 1366, Do not forget to add reference to System.Numerics;

BigInteger i = 1;
         i = i << 1000;
        char[] myBigInt = i.ToString().ToCharArray();
        long sum = long.Parse(myBigInt[0].ToString());
        for (int a = 0; a < myBigInt.Length - 1; a++)
        {
            sum += long.Parse(myBigInt[a + 1].ToString());
        }
        Console.WriteLine(sum);