Hecho general: 771 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 771 is the number of intersections when all the diagonals of a regular 14-gon are drawn.
Trivia: 771 is an unremarkable number.
Fecha histórica: February 9th is the day in 1895 that William G. Morgan creates a game called Mintonette, which soon comes to be referred to as volleyball.