Multiply or divide numbers larger than 38 digits in objective c

Question

I am writing an app that , among other things will be able to multiply or divide very large numbers by number 19 - Those large numbers could possibly span hundreds of digits . Do you know of a library I could use for that? Thanks in advance. I have tried using NSDecimalNumber but its not able to produce results past 38 digits.

Answer 1

If licensing is not an issue GMP is good.