Fatto generale: 21601 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21601 is an unremarkable number.
Trivia: 21601 is an uninteresting number.
Data storica: February 20th is the day in 1998 that American figure skater Tara Lipinski becomes the youngest gold-medalist at the Winter Olympics in Nagano, Japan.