Not that I think I have any special wisdom, far from it, but it may be that this prophecy has already been fulfilled, at least on one level (most prophecy has multiple levels).
...calculate the number of the beast...
6 + 6 + 6 = 18, 1 + 8 = "9"
Calculating the Number for Your Name
...for it is the number of a man...
The beast is government. Government (the beast) has issued each of us our number (i.e., our SSN). Our number is composed of "9" digits (i.e., 'the number of a man')
What are the odds?
It goes without saying how difficult living in our country today, would be without a SSN.
For it is a number (sum total, enumeration) of man [kind]...
An accounting of souls, their order of business, be it with God, or mammon.
The king of Salem ("peace" which is rooted in wholeness, completeness) was MelchiTzedek, "*my* king is righteousness". His name says who/what he is ruled by. The "order" of Melchizedek is his order: how he conducts his business, his manner of doing things. His king is righteousness, and tzedakah is charity which is rooted in righteousness. It is *this* order of business, speech, conduct in which the Messiah is a priest forever. Axiomatic. Says what he means, means what he says. Honest, sincere, gracious, charitable in all things. This is the ideological framework of one whose "king" (rules to live by) is righteousness.
Those on the "other side" would thus decare by their manner, speech, business dealings and so forth that "my king is wickedness". It's how they choose to conduct themselves. Who their "king" (rules to live by) is = who they are.
Souls, livelihoods - how they obtain a paycheck - think butler and baker. Both in jail, but one is restored; one is hanged. Both caused some offense, but one offense did not reflect the character, whereas the other offense was just more of the same old same old. Therefore, each according to his interpretation.
The answer to the mystery in Revelation is in those concepts somewhere. In Torah the reading is Parshat Ki Tisa. On that note, in the verses about the counting of heads for the census and the atonement of souls, the phrase "all who pass among those who are numbered" is written twice. It has a value of 666. Too much to write about the root words and where they lead, but the point is it is a phrase that describes an enumeration of persons, of souls.
There is much in the Jewish commentaries about this business of "How does a coin atone for a soul". A coin is physical, a soul is spiritual. So how does that work, etc. Fascinating stuff. See the midrash about Moses and a coin of fire.
Twenty is the age in which to pursue a livelihood (Pirkei Avot 5:22), so the coins come from the givers' *pursuit* in life. The order/manner of that business and what effect giving that coin had would be like the quantum conundrum about observation determining the properties of an object. Not so weird after all. When Pharaoh observed, one came alive, one became dead. You want the universe to give you a dead cat, it'll give you a dead cat. Each according to his interpretation. :)
SSNs are required by the gov in order to work. But what are those people doing when they are "at work"? The love of money being the root of all evil... What will their souls choose to embrace? Who/what is their king?