(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.

A number used without application to things, e.g. 6, 8, 10; but when applied to anything, e.g. 6 feet, 10 men, it becomes concrete.

(astronomy) A catalogue number used to identify any one of more than one hundred galaxies, nebulae, and other deep-sky objects visible in the night sky; the designation formed by the surname Messier or letter M being prepended to the number, as in Messier 31 or M31 (the Andromeda Galaxy).

(chemistry) the number of molecules that are associated together to form a micelle

plural of deficient number

(usually used attributively) A simple drawing exercise, intended especially for children, consisting of a line drawing that divides the artwork into distinct spaces, the intended color of each indicated by a number and referenced from a key.

To complete such an exercise; to carry out such a technique by filling in each space with the appropriate color.

alternative form of color by number / (rare) plural of color by number

alternative form of color by number

A memorable mobile phone number.