Fait général: 4009 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 4009 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Culture générale: 4009 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: December 22nd is the day in 1920 that the GOELRO economic development plan is adopted by the 8th Congress of Soviets of the Russian SFSR.