Fait général: 6724 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 6724 is an unremarkable number.
Culture générale: 6724 is an uninteresting number.
Date historique: May 29th is the day in 1919 that Albert Einstein's theory of general relativity is tested (later confirmed) by Arthur Eddington and Andrew Crommelin.