Symbolic Meaning of a Safe Without Door?

I recently had a dream where there was a safe in my room. The safe was face down and when i turned it over there was no door. There was nothing on the inside of the safe except three numbers in a vertical column: 98 63 87. These numbers seem really high for a safe combination. I later found the door to the safe in my dream and there was no combination lock on the front of the door. What is the meaning of the safe without a door?