Fait général: 6525 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 6525 is a centered icosahedral number.
Culture générale: 6525 is an uninteresting number.
Date historique: November 11th is the day in 1675 that Gottfried Leibniz demonstrates integral calculus for the first time to find the area under the graph of y = ƒ(x).