Fait général: 6424 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 6424 is the number of minimal covers of a set containing 6 elements.
Culture générale: 6424 is an unremarkable number.
Date historique: August 2nd is the day in 1937 that the Marihuana Tax Act of 1937 is passed in America, the effect of which is to render marijuana and all its by-products illegal.