Hecho matemático: 91773 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 91773 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: April 7th is the day in 1827 that John Walker, an English chemist, sells the first friction match that he had invented the previous year.