Fatto generale: 16 is the number of teams that qualified for the finals of the FIFA World Cup from 1934 through 1978 (although for various reasons, only 15 competed in the 1938 and 1950 finals).
Fatto matematico: 16 is the base of the hexadecimal number system, which is used extensively in computer science.
Trivia: 16 is the minimum age that one can drop out of school in most states of the US (however, restrictions apply and vary depending on state).
Data storica: January 16th is the day in 1581 that the English Parliament outlaws Roman Catholicism.