Fatto generale: 21016 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21016 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21016 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: July 15th is the day in 1888 that the stratovolcano Mount Bandai erupts killing approximately 500 people, in Fukushima Prefecture, Japan.