A googolplex is the number 10, which can also be written as the number 1 followed by a googol of zeros (i.e. 10 zeros).
In 1938, Edward Kasner's nine-year-old nephew Milton Sirotta coined the term googol; Milton then proposed the further term googolplex to be "one, followed by writing zeroes until you get tired". Kasner decided to adopt a more formal definition "because...
