Fatto matematico: 81635 is an uninteresting number.
Trivia: 81635 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: July 5th is the day in 2009 that Roger Federer wins a record 15th Grand Slam title in tennis, winning a five set match against Andy Roddick at Wimbledon.