(mathematics) An integer / (mathematics) A natural number (positive or non-negative integer)

(mathematics) Of or relating to number theory.

(mathematics) The branch of pure mathematics concerned with the properties of integers.

(mathematics) A complex number consisting of more than two square roots of negative one, creating multiple simulated dimensions.

(quantum mechanics) One of certain integers or half-integers that specify the state of a quantum mechanical system (such as an electron in an atom).

(physics, chemistry) The total number of protons and neutrons in an atomic nucleus. Symbol: A

A telephone number not listed in the directory.

A number whose decimal representation ends in one or more zeroes. / A rough approximation, especially one whose decimal representation ends in one or more zeroes.

(computing) A number represented by the binary digits 0 and 1.

(set theory) Any cardinal or ordinal number which is larger than any finite, i.e. natural number; often represented by the Hebrew letter aleph (ℵ) with a subscript 0, 1, etc.