WHAT DOES THE NUMBER 666 MEAN?

Either the number is a cryptic way of identifying an actual person (equal to the sum of the numeric equivalents of the letters in a name), or it is a symbol of evil. The latter interpretation derives form the idea of perfection associated with the number seven (seven days of Creation, seven lampstands, etc.) and the idea of completion associated with the number three (the three persons of the Trinity). By these terms, the number six repeated three times would indicate complete imperfection, that is, evil.

This fits the profile of the Beast described here. Some early commentators thought that Nero, emperor of Rome (A.D. 54-68) and a persecutor of Christians, was identified in this text. The numerical value of this name in Hebrew equals 666.

Revelation 13:18 – ¹⁸ Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.