general_fact: 720 is five gross (= 500 duodecimal, 5 × 144).
math_fact: 720 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 720 is the number of degrees in two circles (= 2 × 360).
historical_date: December 20th is the day in 2007 that Elizabeth II becomes the oldest ever monarch of the United Kingdom, surpassing Queen Victoria, who lived for 81 years, 7 months and 29 days.