Fatto generale: 86640 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 86640 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 86640 is an unremarkable number.
Data storica: March 18th is the day in 1965 that Cosmonaut Aleksei Leonov, leaving his spacecraft Voskhod 2 for 12 minutes, becomes the first person to walk in space.