'Forty one' in the Bible

And Rehoboam the son of Solomon reigned in Judah. Rehoboam was forty-one years old when he began to reign, and he reigned seventeen years in Jerusalem, the city that Jehovah had chosen out of all the tribes of Israel to put his name there; and his mother's name was Naamah, an Ammonitess.

and he reigned forty-one years in Jerusalem; and his mother's name was Maachah, daughter of Abishalom.