Hecho matemático: 8631 is a value of n for which 3n and 7n together use each digit exactly once.
Trivia: 8631 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: August 18th is the day in 1958 that Brojen Das from Bangladesh swims across the English Channel in a competition, as the first Bangali as well as the first Asian to ever do it.