User blog comment:Swooped me in one hit/wollion/@comment-29310326-20170213190906/@comment-30754445-20170213202017

Much smaller than a Megiston.

The exact definition isn't clear, though. Is it 5↑(6↑↑googolplex)? Or 5*(6↑↑googolplex)? Or 5 followed by 6↑↑googolplex zeros? The wording is ambiguous.

Luckily it doesn't really matter. All these numbers are indistinguishable from 10↑↑googolplex = 10↑↑10↑10↑100 = FEE100 = FFEEE2 ~ FF3.3 ~ G2.52

That's less than a Great Mega:

Great Mega = 3 in a pentagon ~ 10↑↑10↑↑10↑10↑40 ~ FFEE40 ~ FFFEEE1.6 ~ FFFF3.2 ~ G4.51

so it's obviously much less than a Megiston (which happens to be very close to 10↑↑↑11 = G11)