Hecho matemático: 21448 is an unremarkable number.
Trivia: 21448 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: September 20th is the day in 1871 that Bishop John Coleridge Patteson is martyred on the island of Nukapu, a Polynesian outlier island now in the Temotu Province of the Solomon Islands.