Quite a few, I guess, but you'd probably be more concerned about how many other domains share the same IP addresses rather than about how many IP addresses this

Quite a few, I guess, but you'd probably be more concerned about how many other domains share the same IP addresses rather than about how many IP addresses this domain resolves to. And the answer seems to be thousands of domains — which in this case doesn't help much as they seem to all be related, but which in other cases might (eg. shared hosting, CDNs…).