Hecho general: 50509 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 50509 is an unremarkable number.
Trivia: 50509 is an unremarkable number.
Fecha histórica: April 15th is the day in 1942 that the George Cross is awarded to "to the island fortress of Malta – its people and defenders" by King George VI.