"You, too, can make up your own very large numbers
and give them strange names. Try it. It has a certain charm, especially
if you happen to be nine."

-Carl Sagan,*Cosmos*

-Carl Sagan,

A googol is the number written as 1 followed by 100
zeroes, or

10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.
Using exponential notation, this can be written as
10^{100}.

A googol is such an incredibly large number that it defies the
imagination. For example, a googol is much greater than
the number of particles in the universe!
The name "googol" was suggested in the 1930's by Milton Sirotta, the nine-year-old nephew of
mathematician Dr. Edward Kasner,
who also suggested the name "googolplex" for the number
10^{googol},
which, if written out in full, would be 1 followed by a
*googol* of zeroes.
More names for big numbers.