Googo- is a prefix used in a system invented by Andre Joyce to create number names.[1] It was invented to give a retroactive meaning to googol (in this system, googo-l = \(100^{50} = 10^{100}\)).


The basic concept of the googo- prefix:

  • Convert a number n to Roman numerals.
  • Take those numerals and apply the googo- prefix.
  • The result is \((2n)^{n}\).

For example, a googocci is a googo- followed by cci. cci is 201, so a googocci is \((201 \cdot 2)^{201} = 402^{201}\).


Improper Roman numerals, such as ic = 99 or vim = 994, are allowed for pronounceability's sake. The following substitutions are also allowed:

  • ij for ii
  • ox or iji for iii
  • em or ump for m
  • ex for x
  • el for l


If you need to use a Roman numeral for a number such as 3,333,333 or 888, you can use a Latin prefix followed by the Roman numeral for the repeated digit. So a googoquadrix \(= (\text{quadrix} \cdot 2)^{\text{quadrix}} = (4\ 9's \cdot 2)^{4\ 9's} = 19,998^{9,999}\).


In Roman numerals, a bar placed over a numeral (except I) multiplies it by 1,000 (e.g. \(\overline{V} = 5,000\)). The equivalent in Joyce's system is the "-bar" suffix. So googovbar \(= 10,000^{5,000}\) and googoumpbar \(= 2,000,000^{1,000,000}\).

Multiple bars are allowed, producing so-called "barbarian numbers." A sequence of bars can be shortened using a Latin prefix: "barbarbarbar" is the same as "quadrabar."

Alternative vowels and G-counts

The googo- prefix can be extrapolated to prefixes with different vowels and different numbers of G's. Using Ackermann's Generalized Exponential Notation:

g-n-g[g]-m-r \(= g(n,r,g(m,r,g))\)


  • n and m are integers ranging from 1 to 8. When placed in the word, they are transformed by the following key: o = 1, oo = 2, ee = 3, or = 4, ie = 5, i = 6, e = 7, and ei = 8.
  • r is a Roman numeral as described above.
  • g is the number of G's in the prefix. This can be either two or three, depending on whether an extra G (indicated by brackets) is included.

Specific numbers


  1. Googology

See also

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