(idiomatic) Superlative; impossible to beat.

(idiomatic) To figure; to do the math.

(arithmetic) A set of numerals for representing numbers.

A measure of the antiknock properties of an automobile fuel; isooctane having an octane number of 100, a fuel with the same antiknock properties as a mixture of 90% isooctane and 10% heptane having an octane number of 90.

(mathematics) Any of several complex numbers that are coordinates of the vertices of a regular polygon of unit radius

Synonym of Greek numeral

Asks the interlocutor to give their phone number for subsequent communication.

(idiomatic) First; foremost; best, often used after its headword.

The most important person, the one who is in charge. / Someone who is top of a ranking, who is ranked first. / Oneself, being considered foremost, as by an egoist.

(physics) The number of neutrons or protons in nuclei which are required to fill the major quantum shells, and thus produce exceptionally stable nuclei: 2, 8, 20, 28, 50, 82 and 126.