general_fact: 415 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 415 is the 10^{th} Iccanobif number, where each term is the reverse of the sum of the previous two numbers.
trivia: 415 is an unremarkable number.
historical_date: February 18th is the day in 1978 that the first Ironman Triathlon competition takes place on the island of Oahu, won by Gordon Haller.