Hecho general: 2591 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 2591 is an unremarkable number.
Trivia: 2591 is an uninteresting number.
Fecha histórica: February 3rd is the day in 1918 that the Twin Peaks Tunnel in San Francisco, California begins service as the longest streetcar tunnel in the world at 11,920 feet (3,633 meters) long.