Convert from megatonne to obolus [Ancient Rome]

Unit Definition (megatonne)
The megatonne is a metric unit of mass or weight equal to one million metric tons (tonnes), one teragram (Tg), or about 2.2046 billion pounds.

Unit Definition (obolus [Ancient Rome])
The obolus [Ancient Rome] is a historic unit of weight or mass. The obol is a very small weight that originated as the weight of a tiny Greek coin. In Rome, the obolus was equal to 1/48 Roman ounce (uncia) or about 0.57 gram.