Fait mathématique: 6388 is an uninteresting number.
Culture générale: 6388 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: June 27th is the day in 2007 that the Brazilian Military Police invades the favelas of Complexo do Alemão in an episode which is remembered as the Complexo do Alemão massacre.