Fatto generale: 8418 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 8418 is the number of necklaces possible with 11 beads, each being one of 3 colors.
Trivia: 8418 is a boring number.
Data storica: January 17th is the day in 1929 that Inayatullah Khan, king of the Emirate of Afghanistan abdicates the throne after only three days into his reign.