Fatto matematico: 63910 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 63910 is an uninteresting number.
Data storica: December 23rd is the day in 1970 that the North Tower of the World Trade Center in Manhattan, New York City is topped out at 1,368 feet (417 m), making it the tallest building in the world.