Fait mathématique: 21418 is an unremarkable number.
Culture générale: 21418 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: August 21st is the day in 1969 that an Australian, Michael Dennis Rohan, sets the Al-Aqsa Mosque on fire, a major catalyst of the formation of the Organisation of Islamic Cooperation.