Hecho general: 64721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 64721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 64721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: March 13th is the day in 1997 that the Phoenix lights are seen over Phoenix, Arizona by hundreds of people, and by millions on television.