An accountant or other person who deals with the calculation of numbers as a profession. / (computing) A program, algorithm, or hardware with a focus on numerical calculation.

(mathematics) Any of the large semiprime numbers to be factored in the RSA Factoring Challenge, a competition from 1991 to 2007 encouraging research into computational number theory.

(UK, New Zealand) A telephone number beginning with 0800; these numbers are free for the caller because the call is paid for by the company or organisation being called.

(idiomatic) To understand a person's character, capabilities, or situation. / Used other than figuratively or idiomatically: see have, someone's, number.

plural of number field

(mathematics) A number in the form of a ratio where the dividend equals the divisor plus one.

(Stephanus pagination) A standard reference number for a section of a given Platonic dialogue, referring to a page in the 1578 translation of Plato’s dialogues by Henricus Stephanus.

collective noun used to indicate a set of a particular number, for example, a dozen

The number of people, statistically, who must be exposed to something in order for one of them to experience an adverse effect.

plural of Numanoid