User blog comment:MachineGunSuper/Help with billillion/@comment-3427444-20171212135130

(1,000,000,000)^(1,000,000,000)^(1,000,000,000) = (1,000,000,000)^10^(9*1,000,000,000) = 10^(9*10^9,000,000,000) ~ 10^9,000,000,001

I would put it between hyper-oct-exitillion and tetralogue.