Fatto generale: 51609 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 51609 is an unremarkable number.
Trivia: 51609 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: April 19th is the day in 1954 that the Constituent Assembly of Pakistan recognises Urdu and Bengali as the national languages of Pakistan.