Fatto matematico: 1225 is the smallest number that can be written as the sum of 4 cubes in 3 ways.
Trivia: 1225 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
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.