BigInteger BitLength - TizzyT

''' BigInteger Bit Length '''
    Private Function BitLen(ByVal TestingNbr As BigInteger) As BigInteger
        Dim Nbr As String = TestingNbr.ToString("X")
        BitLen = Convert.ToString(Convert.ToInt32(Nbr(0), 16), 2).TrimStart("0").Length
        BitLen = BigInteger.Add(BitLen, BigInteger.Multiply(New BigInteger(4), New BigInteger(Nbr.Length - 1)))
    End Function