Fait général: 21424 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21424 is a boring number.
Culture générale: 21424 is an uninteresting number.
Date historique: August 27th is the day in 2009 that the Burmese military junta and ethnic armies begin three days of violent clashes in the Kokang Special Region.