Fatto generale: 721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 721 is the smallest number which can be written as the difference of 2 cubes in 2 ways.
Trivia: 721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: December 21st is the day in 1937 that Snow White and the Seven Dwarfs, the world's first full-length animated feature, premieres at the Carthay Circle Theater.