Fatto matematico: 9809 is a stella octangula number.
Trivia: 9809 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: November 8th is the day in 1973 that the right ear of John Paul Getty III is delivered to a newspaper together with a ransom note, convincing his father to pay 2.9 million USD.