oh so you mean like 40trillion 40T
it seems like he has used the first letter and if needed the last letter as well.
Quintilian Qn - i have gotten up to here
i have not gotten so i'm guessing after this point.
Septillion Sn or Sp
i doubts any one can get this high yet unless new update or you have maxed ever thing out.
witch would tack some time lol https://en.wikipedia.org/wiki/Names_of_large_number
use that site