Archangel - αρχαγγελος (ar-khang’-el-os)
Archangel is a classification of angels who have great rank and power. The total number of archangels are unknown having never been revealed in scripture. The term "archangel" is used in only two (2) places in the New Testament and it is not used in the Old Testament.
I Thess 4:16 - "For the Lord Himself with descend from heaven with a shout, with the voice of the archangel, and with the trumpet of God, and the dead in Christ shall rise first."
Jude 9 - "But Michael the archangel when he disputed with the devil and argued about the body of Moses, did not dare pronounce against him a railing judgment, but said, 'The Lord rebuke you.'"
Michael is called the "official" or "prince" over Israel in Daniel 10:13. He is considered one of the "chief princes" mentioned in Daniel 10:13 involved in the angelic battle against the demons which influenced the leadership of Persia and Greece. This reference gives us the only indication that there might be more than one archangel. Their number is something that God has chosen not to reveal to mortal men.
Michael is the only angel identified as an archangel in the Bible. However, most scholars believe that Lucifer and Gabriel are probably archangels.
Jewish writings consider seven angels as archangels. Among those seven archangels tradition names at least four (4) by name: Michael, Gabriel, Raphael, and Uriel. This is not proven by Scripture, however, this assumption is based on Revelation 8:2 which mentions "the seven angels who stand before God." The Bible does not name archangels nor does it describe their duties.
Gabriel and Lucifer are considered to be archangels by many scholars. However, neither is designated in the Scriptures with this description.