Fatto matematico: 4396 is 157 × 28 and each digit is contained in the equation exactly once.
Trivia: 4396 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: January 13th is the day in 1985 that a passenger train plunges into a ravine in Ethiopia, killing 428 in the worst railroad disaster in Africa.