In the sixth aliyah Avrohom remarries, but Rashi says his wife was the original Hagar that he was married to before. And in this aliyah, Avrohom Avinu passes away at the age of 175, and Yitzchak and Yishmael bury their father in the cave of Machpella where Sarah, his wife, and Adam and Chava, are also buried.