Hecho general: 21897 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 21897 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21897 is an unremarkable number.
Fecha histórica: December 13th is the day in 1981 that General Wojciech Jaruzelski declares martial law in Poland to prevent dismantling of the communist system by Solidarity.