math_fact: 87920 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 87920 is an unremarkable number.
historical_date: September 18th is the day in 1870 that Old Faithful Geyser is observed and named by Henry D. Washburn during the Washburn-Langford-Doane Expedition to Yellowstone.