Hecho matemático: 23921 is an uninteresting number.
Trivia: 23921 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: June 28th is the day in 1896 that an explosion in the Newton Coal Company's Twin Shaft Mine in Pittston City, Pennsylvania results in a massive cave-in that kills 58 miners.