Fatto generale: 21389 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21389 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 21389 is an uninteresting number.
Data storica: July 23rd is the day in 1983 that the Sri Lankan Civil War begins with the killing of 13 Sri Lanka Army soldiers by the Liberation Tigers of Tamil Eelam Terrorist group.