What is a googol?
A googol is the number 1 followed by 100 zeros, or 10 to the power of 100. The search engine Google was named after it, with a deliberate change in spelling.
The American mathematician Edward Kasner introduced the googol in his 1940 book Mathematics and the Imagination, written with James Newman. He said the name was suggested by his nine-year-old nephew, Milton Sirotta. Kasner wanted a fun way to show the difference between a huge number and infinity.
A googol is far bigger than anything we can count. Scientists estimate that the observable universe contains about 10 to the power of 80 atoms, which is a hundred billion billion times less than a googol.
Even bigger: the googolplex
Kasner's nephew also proposed the googolplex, which is 1 followed by a googol of zeros. It is so large that it could not be written out in full, because there are not enough atoms in the universe to hold all the zeros. When Larry Page and Sergey Brin named their search engine in 1998, they changed the spelling to Google.
Did You Know?
Big numbers like these appear in physics and computing. For example, the number of possible ways to arrange a standard deck of 52 cards is about 8 followed by 67 zeros.