Fatto generale: 775 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 775 is the smallest number whose 9^{th} power has 26 digits.
Trivia: 775 is an uninteresting number.
Data storica: February 13th is the day in 1967 that American researchers discover the Madrid Codices by Leonardo da Vinci in the National Library of Spain.