1) When calling a phone with caller ID enabled, your number will be displayed on the screen of the other party's mobile phone;
2) If your number is not in the service area, you can call the local customer service number 100 10, and the customer service representative will inquire for you;
3) Generally, after receiving the sim, the mobile phone will write its own phone number, which depends on the function of the mobile phone. For example, for iphone, you can select settings > phone to query.
If the above methods cannot be inquired, please contact the local Unicom manual customer service for consultation.