Fait général: 2178 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 2178 is the only number known which when multiplied by its reverse yields a 4^{th} power.
Culture générale: 2178 is an unremarkable number.
Date historique: December 17th is the day in 1989 that the first episode of television series The Simpsons, "Simpsons Roasting on an Open Fire", airs in the United States.