Jeffyillion

Jeffyillion is the largest number 10⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹⁹ after Bicepillion, followed by Jeffytroniumillion, and the fourth largest number, Centillion 10³⁰³. It was initially coined to refer to the age of the Universe, as it was created in 999 Jeffyillion BC (Big Chromosome).

The population of Steam City is known to have reached the Jeffyillions, nobody knows what the fuck will happen once it surpasses 999 Jeffyillion but all signs point to terrible things.