Fait général: 21706 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21706 is a boring number.
Culture générale: 21706 is a boring number.
Date historique: June 5th is the day in 1956 that Elvis Presley introduces his new single, "Hound Dog", on The Milton Berle Show, scandalizing the audience with his suggestive hip movements.