Trecillion

The trecillion is equal to \(10^{3\left(10^{39}\right)+3}\), or \(10^{3\text{ duodecillion }3}\). The term was coined by Jonathan Bowers. It is 3×1039+4 digits long.

Trecillion is also known as one milliamilliamilliamilliamilliamilliamilliamilliamilliamilliamilliamilliamilliatillion according to Landon Curt Noll's The English name of a number.

Etymology
The name of this number is based on the suffix "-illion" and the prefix "treco-".