First off, infinity isn’t a number, it’s just a useful word to describe something that never ends. So what is the largest actual number?
A googol is a one followed by 100 zeroes – 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000. This number was named by a nine year-old boy called Milton Sirotta. He also suggested the number ‘googolplex’ as “one, followed by writing zeroes until you get tired”, but this got changed to a one followed by a googol zeroes. Wolfgang Nitsche has published a full googolplex online; his ‘book’ has 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 volumes, each containing a million zeroes.
A googolplex is bigger than the number of atoms in the universe, but it’s still not the biggest number. ‘Graham’s number’ is so large it needs to be described using special mathematical symbols. We do know it ends with a seven, though.
Apparently some even bigger numbers have been used in mathematical papers, but no-one really seems to be counting; after all, you can easily break this record by just adding one.
Lachlan Writes Science 