If you forgot your Digi Mobile Number you can use the following USSD Code to find your own Number.
Find my Digi Number
Dial *126# gold
Dial *124# gold
Dial *128#
If the above options not working then
Dial your friends Mobile number, your number will be displayed in his screen 🙂
Find Digi SIM Number
You can find the 16-digit serial number printed on the sim card itself