Fatto generale: 21386 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21386 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21386 is an uninteresting number.
Data storica: July 20th is the day in 1960 that the Polaris missile is successfully launched from a submarine, the USS George Washington, for the first time.