large #s?

I'm trying to work on a prime factorization program, but need a really really big type. One that holds at least 50 decimal digits. Is there such a thing? It would be very good if it was some type of float as well. I know the double is large, but I'm not sure how accurate it is.

http://msdn.microsoft.com/library/de...ype_Ranges.asp

In APCS we use a class called BigInt. It stores the # as an array of chars. It is really slow but you can use numbers that are thousands of digits long. You might want to look into making something like that.

I believe long double is a type, try that.