Anybody who reaches [Nirvana][1] is considered Enlightened / [Arahat][2]. The Buddha is Enlightened. An Arahat is a word for an Enlightened being. Hence Buddha is also an Arahat.

Since the Nirvana for any person is the same the attainment of Arahatship is the same, though on other aspects the Buddha's faculties, [powers][3], attainments, insights and [knowledges][4] are far superior due to his [Paramis][5].


  [1]: http://en.wikipedia.org/wiki/Nirvana
  [2]: http://en.wikipedia.org/wiki/Arhat
  [3]: http://en.wikipedia.org/wiki/Miracles_of_Gautama_Buddha
  [4]: http://en.wikipedia.org/wiki/Abhij%C3%B1%C4%81
  [5]: http://en.wikipedia.org/wiki/P%C4%81ramit%C4%81