Fatto matematico: 679 is the smallest number with multiplicative persistence 5.
Trivia: 679 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: November 9th is the day in 1985 that Garry Kasparov, 22, of the Soviet Union becomes the youngest World Chess Champion by beating Anatoly Karpov, also of the Soviet Union.