Fatto generale: 12159 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 12159 is a boring number.
Trivia: 12159 is a boring number.
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.