Fatto generale: 2591 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 2591 is an uninteresting number.
Trivia: 2591 is an uninteresting number.
Data storica: February 3rd is the day in 1870 that the Fifteenth Amendment to the United States Constitution is ratified, guaranteeing voting rights to citizens regardless of race.