Fatto generale: 15809 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 15809 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 15809 is a boring number.
Data storica: April 13th is the day in 1970 that an oxygen tank aboard Apollo 13 explodes, putting the crew in great danger and causing major damage to the spacecraft while en route to the Moon.