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.
... 18, 5.0% from 18 to 24, 26.8% from 25 to 44, 27.7% from 45 to 64, and 19.9% who are 65 years of age or older. The median age is 43 years. For every 100 females there are ...