The dueicosillion is equal to \(10^{3\left(10^{66}\right)+3}\) or \(10^{3\text{ unvigintillion }3}\).[1] The term was coined by Aarex Tiaokhiao.


Notation Lower bound Upper bound
Arrow notation \(1000\uparrow(1+10\uparrow66)\)
Down-arrow notation \(1000\downarrow\downarrow23\) \(742\downarrow\downarrow24\)
Steinhaus-Moser Notation 40[3][3] 41[3][3]
Copy notation 2[2[67]] 3[3[67]]
H* function H(H(21))
Taro's multivariable Ackermann function A(3,A(3,219)) A(3,A(3,220))
Pound-Star Notation #*((1))*(0,5,0,4,1)*5 #*((1))*(1,5,0,4,1)*5
BEAF {1000,1+{10,66}}
Hyper-E notation E(3+3E66)
Bashicu matrix system (0)(1)[14] (0)(1)[15]
Hyperfactorial array notation (50!)! (51!)!
Fast-growing hierarchy \(f_2(f_2(214))\) \(f_2(f_2(215))\)
Hardy hierarchy \(H_{\omega^22}(214)\) \(H_{\omega^22}(215)\)
Slow-growing hierarchy \(g_{\omega^{\omega^{\omega6+6}3+3}}(10)\)


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