Several. / Several of.

(Canada) A nine-digit number issued by the government of Canada to citizens, permanent residents, and some categories of temporary residents, for official identification in the provision of government services and income taxation. Abbreviation: SIN.

(physics, chemistry) The number of protons in an atom. Symbol: Z

(mathematics) a positive integer {1, 2, 3, ...} / (mathematics) a non-negative integer {0, 1, 2, ...}

(complex analysis) A number of the form a + bi, where a and b are real numbers and i denotes the imaginary unit

Used other than figuratively or idiomatically: see random, number. / A number allotted randomly using suitable generator (electronic machine or as simple "generator" as die).

(number theory) An abundant number.

(number theory) A deficient number.

(number theory) A number that is greater than the sum of all of its divisors except itself.

(number theory) A number that is the sum of all of its divisors except itself.