Fatto generale: 21207 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21207 is a boring number.
Trivia: 21207 is an unremarkable number.
Data storica: January 22nd is the day in 1877 that Arthur Tooth, an Anglican clergyman is taken into custody after being prosecuted for using ritualist practices.