If you have an iPhone
Phone Number: Settings > Phone > My Number
SIM Number: Settings > General > About > ICCID entry shows SIM card number.
If you have an Android
Phone Number: Settings > More > About Device > Status > My Phone number
SIM Number: Remove the back cover and battery from your phone, the SIM Number is located on the SIM Card.
If you have a basic or Feature Phone:
Phone Number: Menu > Prepaid > Phone Number
SIM Number: Menu > Prepaid > SIM Number