Fatto generale: 7776 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 7776 is a 5^{th} power whose digits are non-increasing.
Trivia: 7776 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: April 15th is the day in 1638 that Tokugawa shogunate forces put down the Shimabara Rebellion when they retake Hara Castle from the rebels.