Fznineteen

Fznineteen is equal to \(19^{19}\) = \(19\uparrow\uparrow2\) = 1,978,419,655,660,313,589,123,979.

Etymology
Fznineteen is made out of the Fz- prefix and nineteen, which ends up becoming \(19^{19}\) when concatenated backwards, or 19 to the power of itself.