Fatto matematico: 4312 is the smallest number whose 10^{th} power starts with 7 identical digits.
Trivia: 4312 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: October 21st is the day in 1987 that Jaffna hospital massacre is carried out by Indian Peace Keeping Force in Sri Lanka killing 70 ethnic Tamil patients, doctors and nurses.