Definition A googol equals to the number 10100, that is, a one followed by one hundred zeros. A googolplex is is ten raised to the power of a googol, i.e., 10(10100).

This is already a huge number. For instance, it is more than the number of atoms in the known universePlanetmathPlanetmath. A googoplex is even larger. In fact, since a googolplex has a googol number of zeros in its decimal representation, a googoplex has more digits than there are atoms in our universe. Thus, even if all matter in the universe were at disposal, it would not be possible to write down the decimal representation of a googolplex [1].


  1. 1.

    A googol is approximately the factorialMathworldPlanetmath of 70. The only prime factorsMathworldPlanetmath in a googol and a googolplex are 2 and 5 [1].

  2. 2.

    Using Stirling’s formulaMathworldPlanetmathPlanetmath we can approximate the factorial of a googol to obtain

  3. 3.

    A googoplex plus one is not a prime. One factor is 316912650057057350374175801344000001 [5].

History and etymology

The googol was created by the American mathematician Edward Kasner (1878-1955) [4] in [2] to illustrate the differencePlanetmathPlanetmath between an unimaginably large number and infinityMathworldPlanetmath. The name ’googol’ was supposedly coined by Kasner’s nine-year-old nephew Milton Sirotta in 1938 when asked to give a name for a huge number. The name googol was perhaps influenced by the comic strip character Barney Google [1, 3]. The name of the search engine google was inspired by the number googol [6].


  • 1 Wikipedia’s on googol.
  • 2 Kasner, Edward&Newman, James Roy,Mathematics and the Imagination, (New York, NY, U SA: Simon and Schuster, 1967; Dover Pubns, April 2001; London: Penguin, 1940, ISBN 0486417034).
  • 3 Douglas Harper’s online dictionary, Googol 12/2003.
  • 4 Wikipedia’s on Edward Kasner.
  • 5 Robert Munafo, page on large numbers.
  • 6 Google corporate information: Milestones.
Title googol
Canonical name Googol
Date of creation 2013-03-22 12:25:31
Last modified on 2013-03-22 12:25:31
Owner Mathprof (13753)
Last modified by Mathprof (13753)
Numerical id 19
Author Mathprof (13753)
Entry type Definition
Classification msc 11-00
Related topic Googolplex