Hecho general: 55567 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 55567 is a boring number.
Trivia: 55567 is an unremarkable number.
Fecha histórica: February 19th is the day in 1649 that the Second Battle of Guararapes takes place, effectively ending Dutch colonization efforts in Brazil.