Hecho general: 21443 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 21443 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21443 is an unremarkable number.
Fecha histórica: September 15th is the day in 1831 that the locomotive John Bull operates for the first time in New Jersey on the Camden and Amboy Railroad.