Fait général: 23909 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 23909 is an uninteresting number.
Culture générale: 23909 is an unremarkable number.
Date historique: June 16th is the day in 1903 that Roald Amundsen commences the first east-west navigation of the Northwest Passage, leaving Oslo, Norway.