Understanding driving a relay with a transistor
For reasons that have little to do with the static calculations in the other answers, I would use a beefier transistor such as the 600mA 2N4401 or a MOSFET. Switching an inductive load is harder on the transistor than switching a resistive load, even with the diode. At some point the full relay coil current is flowing through the transistor for a short period of time with more than 12V across it. SOA is unspecified on many of the small transistors.
Give a 2N4401 a few mA of base current and it will be happy switching your inductive 53mA load, and don't forget the diode across the coil. If you need to operate in extreme cold conditions, 5 or 6mA would be better.