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 unremarkable number.
Trivia: 2591 is a boring number.
Data storica: February 3rd is the day in 1112 that Ramon Berenguer III of Barcelona and Douce I of Provence marry, uniting the fortunes of those two states.