Is 51472 a scam

If you were not doing something that needs a code, ignore and delete and move on.

More generally, Apple only contacts you if you contacted them first, either directly contacting support or such, or by doing something that prompts for and requires a two-factor code, or other such.

Sending numbers can be spoofed too, so any messages from any sender can potentially be suspect.

I got a one of those at least a year ago. It's not only meaningless, it's a scam.