# Natural number

#### Dear Wikiwand AI, let's keep it short by simply answering these key questions:

Can you list the top facts and stats about Non-negative integer?

The natural numbers form a set. Many other number sets are built by successively extending the set of natural numbers: the integers, by including an additive identity 0 (if not yet in) and an additive inverse n for each nonzero natural number n; the rational numbers, by including a multiplicative inverse ${\displaystyle 1/n}$ for each nonzero integer n (and also the product of these inverses by integers); the real numbers by including the limits of (converging) Cauchy sequences of rationals; the complex numbers, by adjoining to the real numbers a square root of −1 (and also the sums and products thereof); and so on.[lower-alpha 3][lower-alpha 4] This chain of extensions canonically embeds the natural numbers in the other number systems.