After about a quintrillion, no-one actually cares too much. Sure, googol and googolplex are used, but what you say about the other large numbers being used in ... most scientific communities is, as far as I can see, bollocks.

They just use exponent notation, even in speech. ("The speed of light is three-times-ten-to-the-eight metres per second" is usually quoted, not three hundred million metres per second.) The same applies to other large and small numbers.

It's a lot easier to work out how many times 2x1013 goes into 4x1020, than to calculate that for twenty trillion and four quintrillion. (answer: 2x107, or twenty million).

But sure, they sound good!