I have this issue too, its because I ported my number from a different carrier. The incorrect number is the one your new carrier issued you till the port finalised, so both numbers are associated on your account, more to do with back end stuff!
You can change the number on the SIM using a phone that can save the number in your SIM. You can do it with iPhone and old Nokia phones (maybe others), you can't with Android.
Generally the options is in Settings/Phone/My Number or something similar. I did it with my new SIM (the one i prepared for the yellow Lumia 920 i'm waiting for) just before posting.
Thanks for that Zacconic, I was able to change mine over using an old Sony Ericsson W810i. Wouldn't work with my N8 or N79.
The problem is linked to how new SIMs are registered to the network and activated. This was a replacement SIM and previously when this is done, it was registered in store. This time I was told to do it over the phone and hence the 11 zeros came up.
All fine now though.