general_fact: 47223 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 47223 is an uninteresting number.
trivia: 47223 is a boring number.
historical_date: April 16th is the day in 1962 that Walter Cronkite takes over as the lead news anchor of the CBS Evening News, during which time he would become "the most trusted man in America".