general_fact: 728 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 728 is the smallest number n where n and n+1 are both products of 5 or more primes.
trivia: 728 is an unremarkable number.
historical_date: December 28th is the day in 1956 that Chin Peng, David Marshall and Tunku Abdul Rahman meet in Baling to try and resolve the Malayan Emergency situation.