Fait général: 21923 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21923 is an unremarkable number.
Culture générale: 21923 is a boring number.
Date historique: January 8th is the day in 1996 that an Antonov 32 cargo turboprop powered plane crashes into the central market in Kinshasa, Zaire killing more than 350 people.