How do programming languages handle huge number arithmetic

Question

For a computer working with a 64 bit processor, the largest number that it can handle would be 2⁶⁴ = 18,446,744,073,709,551,616. How does programming languages, say J

Answer 1

In general, the language itself doesn't handle high-precision, high-accuracy large number arithmetic. It's far more likely that a library is written that uses alternate numerical methods to perform the desired operations.

For example (I'm just making this up right now), such a library might emulate the actual techniques that you might use to perform that large number arithmetic by hand. Such libraries are generally much slower than using the built-in arithmetic, but occasionally the additional precision and accuracy is called for.