The patent number can only be used by the patentee, that is, the patentee has the right to mark patent information on its patented products. Patented products must be legally produced with the consent of the patentee. The same goes for patented methods, which can only be used by others with the consent of the patentee.
From a publicity perspective, sellers of patented products either have the permission of the patentee to sell patented products, or purchase legitimate patented products from legitimate channels. In both cases, when advertising Patent information can be used.
If the patent mark (the patent number you mentioned) is marked on a non-patented product, it is illegal!
I don’t know what specific situation you encountered. This is what I can think of. I hope it helps.