'Twenty one' in the Bible

Zedekiah was twenty one years old when he began to reign and he reigned eleven years in Jerusalem. His mother's name was Hamutal the daughter of Jeremiah of Libnah.

And Zedekiah was twenty one years old when he began to reign, and reigned eleven years in Jerusalem.

Zedekiah was twenty one years old, when he was made king, and he reigned eleven years in Jerusalem. His mother's name was Hamutal, Jeremiah's daughter of Libnah.

had not the prince over the kingdom of the Persians withstood me twenty one days. But lo, Michael, one of the chief princes, came to help me; him have I left by the king of Persia,