Legion's number of the second kind

Legion's number of the second kind is equal to \(666!^{666!} \approx 10^{1.609941\times10^{1,596}}\), where \(666!\) represents the factorial of 666.Legion's Numbers from Wolfram MathWorld
==Approximations==
Notation 	Lower bound 	Upper bound
Arrow notation 	\(770\uparrow338\uparrow631\) 	\(601\uparrow409\uparrow611\)
Down-arrow notation 	\(237\downarrow\downarrow673\) 	\(596\downarrow\downarrow576\)
Steinhaus-Moser Notation 	576[3][3] 	577[3][3]
Copy notation 	1[1[1597]] 	2[2[1597]]
H* function 	H(536H(530)) 	H(537H(530))
Taro's multivariable Ackermann function	A(3,A(3,5301)) 	A(3,A(3,5302))
Pound-Star Notation 	#*((1))*((92))*17 	#*((1))*((93))*17
BEAF 	{770,{338,631}} 	{601,{409,611}}
Hyper-E notation 	E[237]672#2 	E[596]575#2
Bashicu matrix system 	(0)(1)[72] 	(0)(1)[73]
Hyperfactorial array notation 	(666!)! 	(667!)!
Fast-growing hierarchy 	\(f_2(f_2(5291))\) 	\(f_2(f_2(5292))\)
Hardy hierarchy 	\(H_{\omega^22}(5291)\) 	\(H_{\omega^22}(5292)\)
Slow-growing hierarchy 	\(g_{\omega^{\omega^{\omega^3+\omega^25+\omega9+6}}}(10)\)	\(g_{\omega^{\omega^{\omega^3+\omega^25+\omega9+6}2}}(10)\)
== See also ==
*Beast number
*Legion's number of the first kind
*Leviathan number
== Sources ==
Category:Numbers
Category:Class 3
Category:Even numbers
Category:Perfect powers
Category:Upper class 3