math_fact: 6773 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 6773 is an uninteresting number.
historical_date: July 17th is the day in 1981 that a structural failure leads to the collapse of a walkway at the Hyatt Regency in Kansas City, Missouri killing 114 people and injuring more than 200.