Sorry, I misunderstood you. The phone number is not stored in the SIM card by default, nor the phone or router.
In your case , you will need to add your phone to the SIM card's phonebook, with the command similar to this:
- gsmctl -A 'AT+CPBW=1,"123",129,"test"'
Then you will be able to retrieve the number with the following command:
To get your number, you can simply send an SMS from the router to a specified phone number by using events reporting functionality.