> Infinity is neither a number nor a quantity. It's not a number, because you can't get there by counting.
That's an oddly narrow implied definition of "number" which, as well as infinity, would exclude everything other than the natural numbers. Maybe it extends to the integers, if you use an unusually generous definition of "counting". But it certainly excludes non-integral rationals, and, a fortiori, all irrationals from the set of "numbers".