Hecho general: 50909 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 50909 is an uninteresting number.
Trivia: 50909 is an uninteresting number.
Fecha histórica: May 20th is the day in 1609 that Shakespeare's sonnets are first published in London, perhaps illicitly, by the publisher Thomas Thorpe.