Fatto generale: 21298 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21298 is an unremarkable number.
Trivia: 21298 is an unremarkable number.
Data storica: April 23rd is the day in 1990 that Namibia becomes the 160th member of the United Nations and the 50th member of the Commonwealth of Nations.