plural of number sign

(idiomatic) A person who holds a position in an organization that corresponds to that held by another person in another organization; a counterpart

The number of protons in an atom.

A number that shares its prime factors with another.

(number theory) A (nonzero) natural number that is expressible as the product of two (or more) natural numbers other than itself and 1.

(physics) A quantum number related to the difference between the numbers of quarks and antiquarks in a system of subatomic particles

(number theory) Any of a series of numbers formed from the sum of the reciprocals of consecutive natural numbers

(mathematics) A number whose decimal representation of its square ends in itself.

(number theory) One of a pair of numbers having the property that the sum of the divisors of each, excluding itself, is equal to the other number.

(physics) The number of neutrons in the nucleus of an atom or isotope. Symbol: N