Hexafact

Hexafact is the mixed factorial of 6, written as 6*. The term was coined by TechKon. It is equal to \((6,561 \uparrow\uparrow 5) \uparrow\uparrow\uparrow 6\).
== Etymology ==
The name of this number is based on Greek prefix "hexa-" and the word "factorial".
== Approximations in other notations ==
Notation 	Approximation
Bird's array notation 	\(\{\{6561,5,2\},6,3\}\) (exact)
BEAF 	\(\{\{6561,5,2\},6,3\}\) (exact)
Graham Array Notation 	\([[6561,5,2],6,3]\) (exact)
Strong Array Notation 	\(s(s(6561,5,2),6,3)\) (exact)
Hyper-E notation 	\(E25043.722136476503\#4\#6\)
Chained arrow notation 	\((6,561 \rightarrow 5 \rightarrow 2) \rightarrow 6 \rightarrow 3\) (exact)
Hyperfactorial array notation	\(10!2\)
Nested Factorial Notation 	\(10![3]\)
Fast-growing hierarchy 	\(f_4(6)\)
Hardy hierarchy 	\(H_{\omega^36+\omega^25}(6,561)\)
Slow-growing hierarchy 	\(g_{\varepsilon_{\zeta_0+1}}(6)\)
== Sources ==
SpongeTechX's Googology World
== See also ==
Category:Numbers
Category:Numbers by SpongeTechX
Category:Up-arrow notation level
Category:Factorial numbers
Category:Powers of 3
Category:Pentation