HI @RamanG,
the number you see +3945117 is the active default and non-changeable setting which is set automatically if the ho.called service is active.
At the following link you will find details on how the service works: https://supporto.ho-mobile.it/t5/Soluzioni-per-usare-la-SIM/Servizi-gratuiti-della-SIM/ta-p/72676
Good evening.