math_fact: 7721 is the smallest value of n for which 3^{n} contains 8 consecutive 3's.
trivia: 7721 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 19th is the day in 197 that Emperor Septimius Severus defeats usurper Clodius Albinus in the Battle of Lugdunum, the bloodiest battle between Roman armies.