Fait général: 42621 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 42621 is a boring number.
Culture générale: 42621 is a boring number.
Date historique: September 9th is the day in 337 that Constantine II, Constantius II, and Constans I succeed their father Constantine I as co-emperors.