"Googoltetraplex" redirects here. It is not to be confused with googolteraplex.

A googolquadriplex is a number equal to one with a googoltriplex zeroes after it, or 1010101010100. The term was coined by Sbiis Saibian. There are several variants of the name of this number, which are unofficially coined by others or are just refered to without sources: googolquadraplex,[citation needed] googoltetraplex,[citation needed] googolplexplexplexplex,[citation needed] googolduplexian,[citation needed] googolplexianiteron,[citation needed] and googolquadruplex by Ravi Kulkarni.

In Hyper-E Notation it can be written E100#5. In down-arrow notation it can also be written $$10 \downarrow\downarrow (10^{10^{10^{100}}}+1)$$. It is 10101010100+1 digits long.

Writing down the full decimal expansion would take 10101010100-6 books of 400 pages each, with 2,500 digits on each page (except for the first, which would have 2,501).

## Etymology

This word was made by combining "googol" (10100) + "quadri-" (4) + "-plex" (10n).

## Approximations in other notations

Notation Approximation
Up-arrow notation $$10 \uparrow 10 \uparrow 10 \uparrow 10 \uparrow 10 \uparrow 100$$ (exact)
Chained arrow notation $$10 \rightarrow 10^{10^{10^{10^{100}}}}$$ (exact)
Hyper-E notation $$\textrm{E}100\#5$$ (exact)
Hyperfactorial array notation $$((((69!)!)!)!)!$$
BEAF $$\{10,\{10,\{10,\{10,\{10,100\}\}\}\}\}$$ (exact)
Fast-growing hierarchy $$f_2^{5}(324)$$
Hardy hierarchy $$H_{\omega^25}(324)$$
Slow-growing hierarchy $$g_{\omega^{\omega^{\omega^{\omega^{\omega^{\omega^2}}}}}}(10)$$ (exact)