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

Ada actually supports this natively, but only for its typeless constants ("named numbers"). For actual variables, you need to go find an arbitrary-length package. See Arbitrary length integer in Ada