General fact: 5709 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 5709 is a structured pentakis dodecahedral number.
Trivia: 5709 is a boring number.
Historical date: August 18th is the day in 1920 that the Nineteenth Amendment to the United States Constitution is ratified, guaranteeing women's suffrage.