Megillion

The megillion is equal to \(10^{3 \cdot 10^{3,000,000}+3}\), or \(10^{3 \cdot 10^{3 \cdot \text{million}} +3}\)  in the system devised by Jonathan Bowers.

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