Hecho matemático: 1581 is the smallest number whose 8^{th} power contains exactly the same digits as another 8^{th} power.
Trivia: 1581 is a boring number.
Fecha histórica: April 29th is the day in 1997 that the Chemical Weapons Convention of 1993 enters into force, outlawing the production, stockpiling and use of chemical weapons by its signatories.