Fatto generale: 260 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 260 is the constant of an 8×8 magic square.
Trivia: 260 is a boring number.
Data storica: September 16th is the day in 1812 that the Fire of Moscow (1812) begins shortly after midnight and destroys three quarters of the city days later.