Fait général: 8669 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 8669 is the maximum value of n so that there exist 5 denominations of stamps so that every postage from 1 to n can be paid for with at most 18 stamps.
Culture générale: 8669 is a boring number.
Date historique: September 25th is the day in 1775 that Ethan Allen surrenders to British forces after attempting to capture Montreal during the Battle of Longue-Pointe.