Hecho general: 4639 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 4639 is an uninteresting number.
Trivia: 4639 is an uninteresting number.
Fecha histórica: September 12th is the day in 1994 that Frank Eugene Corder crashes a single-engine Cessna 150 into the White House's south lawn, striking the West wing and killing himself.