Hecho matemático: 9643 is the smallest number that can not be formed using the numbers 2^{0}, 2^{1}, ... , 2^{7}, together with the symbols +, –, × and ÷.
Trivia: 9643 is an unremarkable number.
Fecha histórica: May 26th is the day in 1828 that Feral child Kaspar Hauser is discovered wandering the streets of Nuremberg.