Googol

A googol is 10^100 (1 followed by 100 zeros). It far exceeds the number of atoms in the observable universe (~10^80).

The googol was coined in 1920 by 9-year-old Milton Sirotta, nephew of mathematician Edward Kasner. Kasner asked his nephew to name a very large number, and "googol" was the result. (Google the company is a deliberate misspelling of this word.)

A googol is incomprehensibly large. The observable universe contains roughly 10^80 atoms. A googol is 10^20 times that, a hundred quintillion universes' worth of atoms. No physical quantity in the known universe comes close to a googol.

Despite its size, a googol is precisely defined and finite. It's useful in mathematics for discussing the boundaries between "very large but finite" and "infinite." It also serves as a humbling reminder that even numbers far beyond physical reality have clear mathematical meaning.

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More terms

BillionOne billion (1,000,000,000) is 10^9, or one thousand millions. A billion seconds is about 31.7 years.GoogolplexA googolplex is 10^googol, or 10^(10^100). It cannot be written out in full because it has more digits than atoms in the universe.InnumeracyInnumeracy is the mathematical equivalent of illiteracy: the inability to understand and work with numbers and basic mathematical concepts.MillionOne million (1,000,000) is 10^6, or one thousand thousands. A million seconds is about 11.5 days.Order of MagnitudeAn order of magnitude is a factor of 10. Two numbers differ by one order of magnitude if one is roughly 10 times the other.View all glossary terms