Hecho general: 91911 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 91911 is an uninteresting number.
Trivia: 91911 is a boring number.
Fecha histórica: August 23rd is the day in 2006 that Natascha Kampusch, who had been abducted at the age of 10, managed to escape from her captor Wolfgang Priklopil, after 8 years of captivity.