Fatto generale: 21044 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21044 is an uninteresting number.
Trivia: 21044 is an uninteresting number.
Data storica: August 12th is the day in 1992 that Canada, Mexico and the United States announce completion of negotiations for the North American Free Trade Agreement (NAFTA).