A random number processing apparatus includes a memory cell and a control circuitry. The memory cell has a characteristic in which a resistance value reversibly shifts between a plurality of resistance value ranges in accordance with an electric signal applied. The control circuitry generates random number data on the basis of a plurality of items of resistance value information obtained, at a plurality of different times, from the memory cell whose resistance value is in a certain resistance value range of the plurality of resistance value ranges. The resistance value of the memory cell randomly changes over time while the resistance value is within the certain resistance value range.