Fatto matematico: 690 is the smallest number that can not be written as the sum of a triangular number, a cube, and a Fibonacci number.
Trivia: 690 is an uninteresting number.
Data storica: November 20th is the day in 1407 that a truce between John the Fearless, Duke of Burgundy and Louis of Valois, Duke of Orléans is agreed under the auspices of John, Duke of Berry.