Mathematical fact: 21223 is an unremarkable number.
Trivia: 21223 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Historical date: February 7th is the day in 1856 that the Kingdom of Awadh is annexed by the British East India Company and Wajid Ali Shah, the king of Awadh, is imprisoned and later exiled to Calcutta.