Fatto generale: 495 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 495 is the Kaprekar constant for 3-digit numbers.
Trivia: 495 is an uninteresting number.
Data storica: May 9th is the day in 1969 that Carlos Lamarca leads the first urban guerrilla action against the military dictatorship of Brazil in São Paulo, by robbing two banks.