Hecho matemático: 2517 is the number of regions the complex plane is cut into by drawing lines between all pairs of 17^{th} roots of unity.
Trivia: 2517 is an uninteresting number.
Fecha histórica: November 21st is the day in 1386 that Timur of Samarkand captures and sacks the Georgian capital of Tbilisi, taking King Bagrat V of Georgia captive.