Fait général: 21204 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21204 is an unremarkable number.
Culture générale: 21204 is an unremarkable number.
Date historique: January 19th is the day in 1795 that the Batavian Republic is proclaimed in the Netherlands bringing to an end the Republic of the Seven United Netherlands.