Fait général: 21540 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21540 is an unremarkable number.
Culture générale: 21540 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: December 21st is the day in 1844 that the Rochdale Pioneers commence business at their cooperative in Rochdale, England, starting the Cooperative movement.