Apple Watch phone number?

I disagree. The only way it can have its own number is

1. if it is paired to another family members watch, and functionality is therefore reduced. or
2. If your iPhone has Dual SIM support, then you can get a 2nd phone number your iPhone on the eSIM and then attach the Apple Watch to that phone number. But it is still essentially the iphone's number.

If I am wrong someone will correct me as network operators around the world have their own rules.

Apple Watches use eSIM, there is no SIM tray

Cellular Watch usually has the same number as the iphone. Network provider issues an eSIM for the additional hardware

Make sure your country has a provider

Apple Watch - Carriers - Apple

LD150, you are NOT wrong.

🙏

You're welcome, glad we could help.