java.math.BigInteger is a part of most standard Java distributions. (It is optional in PersonalJava or other minimal JavaLanguage profiles.) It allows arbitrary-size integers to be represented, including some more common mathematical operations on big numbers. As a practical matter, most implementations limit the size of a number to approximately 2 billion digits (and that's an incredibly big number). The performance of different BigInteger packages varies greatly. In fact, the performance of the library varies greatly between different releases of Sun's Java Virtual Machine. Sun's is one of the very slowest, using only the most naïve implementations of algorithms for multiplication and base conversion. The Kaffe project uses the GMP libraries to provide extremely fast BigInteger calculations, which are thousands of times faster than Sun's implementations for large numbers. ---- CategoryJava