Fait général: 21290 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21290 is an uninteresting number.
Culture générale: 21290 is a boring number.
Date historique: April 15th is the day in 1943 that an Allied bomber attack misses the Minerva automobile factory and hits the Belgian town of Mortsel instead, killing 936 civilians.