septillian
A sextillian is a thousand pentallion, which in turn is a thousand quadrillion, which is a thousand billion. That makes it:Sextillian = 1000 * Pentallion= 1000 * 1000 * Quadrillion= 1000 * 1000 * 1000 * Trillion= 1000 * 1000 * 1000 * 1000 * Billion= 1000 * 1000 * 1000 * 1000 * 1000 * Million= 1000 * 1000 * 1000 * 1000 * 1000 * 1000 * Thousand= (10^3)^6 * Thousand= 10^21That makes it 21 zeroes!