Fatto matematico: 4370 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 4370 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: December 18th is the day in 1271 that Kublai Khan renames his empire "Yuan" (元 yuán), officially marking the start of the Yuan Dynasty of Mongolia and China.