math_fact: 47173 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 47173 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 25th is the day in 1928 that Charles Jenkins Laboratories of Washington, D.C. becomes the first holder of a television license from the Federal Radio Commission.