The ennacthulhum (also called ogdacthularxihect) is equal to E100#^^^^^^^#100 = E100#{7}#100 in Extended Cascading-E Notation.[1] The term was coined by Sbiis Saibian.


The name of this number is based on the words "enneation" and "Cthulhu".

Approximations in other notations

Notation Approximation
BEAF \(\{X,X,1,6\}\ \&\ 100\)
Bird's array notation \(\{100,6 [1 [2\neg3] 2] 2\}\)
Hyperfactorial array notation \(100![1] w(1)/5\)
Fast-growing hierarchy \(f_{\varphi(5,0,0)}(99)\)
Hardy hierarchy \(H_{\varphi(5,0,0)}(100)\)
Slow-growing hierarchy \(g_{\vartheta(\Omega_{2}5)}(100)\)


  1. Saibian, Sbiis. 4.3.4 - Forging Extended Cascading-E Numbers Part II. Retrieved June 2014.
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