Fatto matematico: 8353 is the smallest number whose 4^{th} power contains 5 consecutive 6's.
Trivia: 8353 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: November 13th is the day in 1841 that James Braid first sees a demonstration of animal magnetism, which leads to his study of the subject he eventually calls hypnotism.