Fait général: 21936 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21936 is a boring number.
Culture générale: 21936 is an unremarkable number.
Date historique: January 21st is the day in 1789 that the first American novel, The Power of Sympathy or the Triumph of Nature Founded in Truth, is printed in Boston, Massachusetts.