Fatto matematico: 6490 is the number of ways to place 2 non-attacking bishops on a 11×11 chessboard.
Trivia: 6490 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: October 7th is the day in 1993 that the Great Flood of 1993 ends at St. Louis, Missouri, 103 days after it began, as the Mississippi River falls below flood stage.