Fait général: 9660 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 9660 is a truncated tetrahedral number.
Culture générale: 9660 is a boring number.
Date historique: June 12th is the day in 1665 that England installs a municipal government in New York City (the former Dutch settlement of New Amsterdam).