'Forty one' in the Bible

Now Rehoboam son of Solomon ruled in Judah. He was forty-one years old when he became king and he ruled for seventeen years in Jerusalem, the city the Lord chose from all the tribes of Israel to be his home. His mother was an Ammonite woman named Naamah.

He ruled for forty-one years in Jerusalem. His grandmother was Maacah daughter of Abishalom.