math_fact: 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.
historical_date: May 26th is the day in 1983 that a strong 7.7 magnitude earthquake strikes Japan, triggering a tsunami that kills at least 104 people and injures thousands.