mobile phone number

(physics, chemistry) atomic number

number (on an athlete's uniform's back); jersey number, uniform number, player number, shirt number

a postal code, a zip code

(computing) line number

(2channel slang) Someone tell me!

my number card, individual number card, ID card, social security card

(formal) [I, we] wish you a happy new year (literally meet a good year)

excuse me; may I come in?

an International Standard Book Number