How to get phone number from iPhone?

///to get know the device is iPhone or iPod touch ...

NSString deviceType = [[UIDevice currentDevice] model] ;

/// if the device is iPhone, pick up the phone number

if ( [deviceType isEqualToString:@"iPhone"] ) {

NSString *num = [[NSUserDefaults standardUserDefaults] stringForKey:@"SBFormattedPhoneNumber"];

NSLog(@"phone number:%@",num) ;

}