Fait mathématique: 9099 is the number of ways to 3-color the faces of a dodecahedron.
Culture générale: 9099 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: November 28th is the day in 1627 that the Polish–Lithuanian Commonwealth Navy has its greatest and last victory in the Battle of Oliva.