Fait mathématique: 6009 is a strobogrammatic number.
Culture générale: 6009 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: June 13th is the day in 1934 that Adolf Hitler and Benito Mussolini meet in Venice, Italy; Mussolini later describes the German dictator as "a silly little monkey".