'Sixty six' in the Bible

All the souls who came with Jacob into Egypt, that came out of his loins, besides the wives of the sons of Jacob, all the souls were sixty-six.

But if she bears a maid-child, then she shall be unclean two weeks, as in her impurity, and she shall continue in the blood of [her] purifying sixty-six days.

Now the weight of gold that came to Solomon in one year was six hundred and sixty-six talents of gold,

The sons of Adonikam, six hundred sixty-six.