Where in the DMCA does it say that
Where in the law does it say that you aren't allowed to stab someone with a screw driver? Nowhere. That doesn't mean it isn't strictly implied.
Secondly, the DMCA isn't of particular interest here: the number might as well constitute a secret pertaining to national security, distribution of which may get you the death penalty for espionage.
The DMCA is of particular interest because it's a potential counterexample of your assertion that other tools or intent are necessary to make distribution of a number illegal. The whole point is that it's a bad law, primarily because it's unclear what it prevents you from doing.
The law is pretty clear, though, on stabbing people and committing espionage.
Where in the DMCA does it say that? And even positing that it does (though I'm pretty sure it doesn't), would that mean my possession of this prime, a linux distro, and this article in my browser history constitutes a crime?
The number itself doesn't break the law: the actions/intent of the user is what breaks the law.
Again, you're not talking about the actual DMCA. The actual DMCA implies that the intent of the user may be irrelevant if the primary purpose of the thing itself is to circumvent DRM tech. That's the whole point: the law is so poorly written and broadly applicable that nobody really knows what you can and can't do under it.