general_fact: 1658 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 1658 is an unremarkable number.
trivia: 1658 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: July 15th is the day in 1955 that Eighteen Nobel laureates sign the Mainau Declaration against nuclear weapons, later co-signed by thirty-four others.