Eighteen is a composite number, its proper divisors being 1, 2, 3, 6 and 9.
18 is the age limit for being allowed a driver's license in many parts of the world.
... New Zealand Prime Minister (1960-1972) February 20 - Alexei Kosygin[?], Premier of the Soviet Union[?] (+ 1980) February 25 - Adelle Davis[?], nutritionist, ...