Fatto generale: 21508 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21508 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21508 is a boring number.
Data storica: November 19th is the day in 1990 that Pop group Milli Vanilli are stripped of their Grammy Award because the duo did not sing at all on the Girl You Know It's True album.