Fatto generale: 4291 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4291 is the number of necklaces possible with 6 beads, each being one of 6 colors.
Trivia: 4291 is a boring number.
Data storica: September 30th is the day in 1906 that the Real Academia Galega, Galician language's biggest linguistic authority, starts working in Havana.