21 (number) – Wikipedia

Age 21. In several countries 21 is the age of majority. See also: Coming of age. In all US states, 21 is the drinking age. However, in Puerto Rico and U.S. Virgin Islands, the drinking age is 18. In California, Hawaii, New York, and New Jersey, 21 is the minimum age that one person may purchase cigarettes and other tobacco products.

: https://en.m.wikipedia.org/wiki/21_(number)