Mahasiddhanta (A Treatise on Astronomy) of Aryabhata

There are eighteen chapters in the 'Mahasiddhanta' of Aryabhata.  In the first chapter which treats of 'Madhyamadhikara', representation of numbers by alphabet is first explained, and then the revolutions and other properties of the planets, and the number of solar and other days in a Kalpa, have been shown.  In the eleventh Sloka of this chapter on the revolutions of planets, the numbers of revolutions of the Great Bear and Ayanagraha, in a Kalpa, are given to be 1599998 and 578159 respectively.