How do I manage my account with just my number ?
I want to remove the iPhone 11 from managing my Apple ID account but keep using the same Apple ID I want just one phone number to manage my Apple id
You need only only one number but an additional is recommended.
Trusted phone numbers
A trusted phone number is a number that can be used to receive verification codes by text message or automated phone call. You must verify at least one trusted phone number to enroll in two-factor authentication.
You should also consider verifying an additional phone number you can access, such as a home phone, or a number used by a family member or close friend. You can use this number if you temporarily can't access your primary number or your own devices.