Fait général: 16781 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 16781 is a boring number.
Culture générale: 16781 is an uninteresting number.
Date historique: December 10th is the day in 1541 that Thomas Culpeper and Francis Dereham are executed for having affairs with Catherine Howard, Queen of England and wife of Henry VIII.