Aryabhata (Sanskrit: आर्यभट listen (help·info); IAST: Āryabhaṭa) or Aryabhata I (476–550 CE) was the first in the line of great mathematician-astronomers from the classical age of Indian mathematics and Indian astronomy. His works include the Āryabhaṭīya (499 CE, when he was 23 years old) and the Arya-siddhanta.
The works of Aryabhata dealt with mainly mathematics and astronomy. He also worked on the approximation for pi.
While there is a tendency to misspell his name as "Aryabhatta" by analogy with other names having the "bhatta" suffix, his name is properly spelled Aryabhata: every astronomical text spells his name thus, including Brahmagupta's references to him "in more than a hundred places by name". Furthermore, in most instances "Aryabhatta" does not fit the metre either.