'Number' in the Bible

Then I looked, and I heard the voice of many angels around the throne and the living creatures and the elders; and the number of them was myriads of myriads, and thousands of thousands,

And there was given to each of them a white robe; and they were told that they should rest for a little while longer, until the number of their fellow servants and their brethren who were to be killed even as they had been, would be completed also.

And I heard the number of those who were sealed, one hundred and forty-four thousand sealed from every tribe of the sons of Israel:

The number of the armies of the horsemen was two hundred million; I heard the number of them.

and he provides that no one will be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name.

Here is wisdom. Let him who has understanding calculate the number of the beast, for the number is that of a man; and his number is six hundred and sixty-six.

And I saw something like a sea of glass mixed with fire, and those who had been victorious over the beast and his image and the number of his name, standing on the sea of glass, holding harps of God.

and will come out to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together for the war; the number of them is like the sand of the seashore.