The largest tweetable number

What is the largest tweetable number?

What is the largest number you can tweet, to use the old terminology for posting on X.com? Constrained by the standard 280 character limit, using only the basic text functionality, what is the largest number that you can describe in a tweet?

The question will lead us on a cosmic journey to some truly astounding numbers and beyond, eventually into the evaporating mist of confusions of logical complexity and paradox, while gradually revealing a fundamental underlying issue of mathematical determinacy—does every mathematical question have a determinate answer?