100000th is syntactically correct. That it's semantically binary rather than decimal is the joke.
> I'm more curious if there's other suffixes to use for this kind of thing when it's not base10
No, of course not ... why would there be?
We don't say oneth, twoth, or threeth, we say first (1st), second (2nd), and third (3rd). For all other digits and numbers not ending with 1, 2, or 3 we use th. So zeroth (0th), tenth (10th), hundredth (100th), hundred thousandth (100000th). Stick 0b in front and it's 0b100000th.
> I'm more curious if there's other suffixes to use for this kind of thing when it's not base10
No, of course not ... why would there be?
We don't say oneth, twoth, or threeth, we say first (1st), second (2nd), and third (3rd). For all other digits and numbers not ending with 1, 2, or 3 we use th. So zeroth (0th), tenth (10th), hundredth (100th), hundred thousandth (100000th). Stick 0b in front and it's 0b100000th.