Question

The number is bigger than int & long but can be accomodated in Decimal. But the normal ToString or Convert methods don’t work on Decimal.

Answer 1

I believe this will produce the right results where it returns anything, but may reject valid integers. I dare say that can be worked around with a bit of effort though… (Oh, and it will also fail for negative numbers at the moment.)

static string ConvertToHex(decimal d) {     int[] bits = decimal.GetBits(d);     if (bits[3] != 0) // Sign and exponent     {         throw new ArgumentException();     }     return string.Format('{0:x8}{1:x8}{2:x8}',         (uint)bits[2], (uint)bits[1], (uint)bits[0]); }