+448719156756 which part of this mobile number

Now what to do if your mobile phone is stolen.
You call your service provider and give them a specific number to deactivate your stolen mobile phone. This system applies to both prepay and postpaid packages.

Every mobile in this world has a unique code called as International mobile equipment identity 'IMEI Number'. This is a unique serial number of every mobile phone. If you provide this serial number to your network operator, they will deactivate your stolen mobile phone. No one can use your mobile phone even if the person who has stolen your mobile, insert new Sim in the mobile. This mobile will be useless for all networks or service providers. All mobile network operators will deactivate or disable the phone by reference to this unique IMEI number of the mobile phone.

How to get this IMEI number?
This number can normally be found under the battery of mobile phone ,looking something like 567800987345687. You can also get this number from the phone software, by entering following useful code. Simply write down on your mobile phone the following code.* # 0 6 #

A 15 digit code will appear on the screen after pressing send button, or in some phones it comes automatically just by writing * # 0 6 #. So whenever you buy a mobile phone, get this code from the battery or simply write above code on your phone and get IMEI number.

After this, record this 15 digit IMEI number and your phone number on your personal note book, place this book at a safe place and that's it. Now suppose if you lost your phone, make a call to your service provider and give them your phone number and this particular key,i.e IMEI number. They will deactivate your stolen mobile phone.
You probably won't get your phone back, but at least you know that whoever stole it can't use/sell it either. If everybody do this, there would be no point in people stealing mobile phones

NOTE
Don't use your mobile in crowded areas or where you might feel unsafe.
So remember this simple code * # 0 6 #.