There is some debate over how many archangels there are. Gabriel is referred to as an archangel by Catholic tradition, but there is no scripture supporting that. The apocryphal 'Book of Enoch' as well as Ephesians 1:21 and Colossians 1:16 was used by Tomas Aquinas and others preceding him, to develop the 'Angelic Hierarchy', but scripture is very vague when it comes to this.
The word "archangel" comes from the Greek αρχάγγελος (archaggělǒs), meaning chief angel, a translation of the Hebrew רב־מלאך (rav-mal'ákh). There are only 2 verses in the NT that say "Archangel", 1 Thessalonians 4:16 and Jude 1:9. They both refer to Michael as the archangel (singular), though Michael is also referred to in the OT, Daniel 10:13-21, as "one of the chief princes" (vs 13) (also translated as chief angels in some translations). So scripture isn't clear as to whether he is one of several/many archangels, or the only one.
It is important to note that Michael is AN angel, and therefore not accorded the same favors that are afforded to Christ (Hebrews 1:5, 2:5), as the author of Hebrews shows how unique the Son of God is, even above the angels, nor will the world be subject to them, unlike Christ, who will reign (Revelation 19:16; Matthew 2:1, 2; 9:35). Also, Jude 1:9 presents Michael as not even have the power to rebuke Satan alone, as he stated "the Lord rebuke you", whereas Christ had the power to rebuke Satan and demons on his own authority (Matthew 4:10, 16:23, 17:18; Mark 8:33; Luke 4:35).