How to create an integer data type with over 1 billion digits in c

I'm working on a prodgect in which I need a huge number, 1 billion dig开发者_如何学运维its. I'm writing in c, though I'll take answers from objective-c.

Also, I'm wondering about this function/data type I found: Biginteger.

I would like to know what language people use this in and if it will help my problem.

Please respond, Frederick

There is the GMP bignum library, if that's what you are asking.
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