(mathematics) The number 1729, one of the taxicab numbers.

Any of many games based upon numbers.

(game theory) Synonym of nimber

plural of Grundy number

plural of L-number

Any of the identification numbers used in an informal system for classifying catfish before they have an scientific name.

plural of carbon number

(organic chemistry) The number of carbon atoms in each molecule of a compound.

plural of occupation number

(physics) The numerical extent to which a quantum state is filled (in a system of many, identical quantum particles)