7.51533626E+109 is an unrealistically large number. If written out it would be:
751533626 followed by 101 zeroes.
Since it's customary to write comma separators between every three digits the number would be:
75,153,362,600,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.
We don't have a word for this order of number (like million, billion, trillion, quadrillion, etc), so one would have to be invented. However 10100 (or E+100) is called a googol, so if we divide 7.51533626E+109 by 1E+100 we get the number 7.51533626E+9 which can be expressed as 7,515,336,260.
So the number could be expressed as seven billion, five hundred and fifteen million, three hundred and thirty-six thousand, two hundred and sixty googols.
In the universe the number of atoms is estimated to be in the order of 1080 (or E+80), so the given number far exceeds the number of atoms in the universe!
This question was submitted in 2019:
https://www.mathhomeworkanswers.org/257876/7-51533626e-109