general_fact: 7737 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 7737 is an uninteresting number.
trivia: 7737 is an unremarkable number.
historical_date: March 7th is the day in 321 that Emperor Constantine I decrees that the dies Solis Invicti (sun-day) is the day of rest in the Empire.