Mathematical fact: 70976 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 70976 is an uninteresting number.
Historical date: April 28th is the day in 1947 that Thor Heyerdahl and five crew mates set out from Peru on the Kon-Tiki to prove that Peruvian natives could have settled Polynesia.