Fatto generale: 91728 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 91728 is an uninteresting number.
Trivia: 91728 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: February 21st is the day in 1613 that Mikhail I is elected unanimously as Tsar by a national assembly, beginning the Romanov dynasty of Imperial Russia.