'Twenty first' in the Bible

In the first month, from the evening of the fourteenth day of the month until the evening of the twenty-first day of the month, you are to eat unleavened bread.

the twenty-first for Jachin, the twenty-second for Gamul,

the twenty-first to Hothir, his sons and his relatives, for a total of twelve;

On the twenty-first day of the seventh month, this message from the LORD came by Haggai the prophet: