There is no format more popular in the world than the representation of Integers: 32-bit and 64-bit strings are used by basically every single computer in existence and there's no practical reason to change that. But I'm curious to know what kind of different, creative representations integers and natural numbers could have.
Are there different ways to represent ints and natural numbers, with interesting mathematical and computational properties (for example, maybe one representation on which "div" is faster than "add"; or things like that)?