The number of Angels is unknown but there are great numbers of them. There is significantly more of a cumulative number of Angels than all of mankind through the ages. The Biblical accounts describe the number of angels using various terms..
“an innumerable company of Angels” (Hebrews 12:22)
“Thousand, thousands and ten thousand times ten thousand” (Daniel 7:10)
“Ten thousand times ten thousand and thousand thousands” (Revelation 5:11)
These number descriptions are not to assert that there are a trillion angels, but that the number of them is overwhelming.
It appears that all Angels were created at the same time and no new Angels are being added to their numbers. Angels are not subject to physical death, or extinction, therefore they do not decrease in number.
Angels are essentially ministering Spirits and do not have physical bodies like humans, despite their ability to appear as human, they don’t have flesh and bones (Hebrews 1:13-14; Luke 24:37-39).
Angels can only be in one place at one time, they have localized presence. Man can encounter Angels without knowing they are Angels at all (Judges 13:13-16; Hebrews 13:2).
Only three angels are identified by name in the Bible: Gabriel (Daniel 8:16), Michael the archangel (Daniel 10:13), and Lucifer the fallen angel (Isaiah 14:12). Yet angelic beings are mentioned 273 times in 34 books of the Bible. While we don’t know exactly how many angels there are, we do know from the biblical accounts, that an exceedingly large number of angels exist.
The book of Hebrews describes a multitude of angels in heaven that are too great to count: “But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,” Hebrews 12:22
Other Bible translations use terms like “innumerable” (ESV), “myriads” (CSB), and “thousands upon thousands” (NIV) to quantify this enormous throng of angels. The picture expands in the book of Revelation: “And I beheld, and I heard the voice of many angels round about the throne and the beasts and the elders: and the number of them was ten thousand times ten thousand, and thousands of thousands;” Revelation 5:11
Other Bible versions use “myriads of myriads” (ESV) and even “millions” (NLT) to express how many angels there are in heaven.
While the Bible leaves the precise number of angels unspecified, some believe there could be as many angels in existence as the total number of humans in all of history. This theory is based on Matthew 18, “Take heed that ye despise not one of these little ones; for I say unto you, That in heaven their angels do always behold the face of my Father which is in heaven.”Matthew 18:10
The passage suggest that individual people, or at least children, have guardian angels to protect them. Jesus was speaking here in general terms regarding the function of angels as protectors of children. In any case, Scripture is clear that angels do guard and protect human beings (Psalm 34:7; 91:11–12; Matthew 18:10; Acts 12:9–15).
The Bible describes different classifications of angels. Some angels—the cherubim and seraphim—are described as winged creatures. Cherubim primarily attend the throne of God as guards, while seraphim attend His throne by offering worship and praise. (Ezekiel 1:4–28; 10:1–22; Isaiah 6:2–6). The Bible speaks of angels of light (2 Corinthians 11:14) and fallen angels (2 Peter 2:4; Jude 1:6).
Angels perform different tasks in the Bible. Some angels are God’s messengers (Daniel 4:13). Other angels are servants of God (Psalm 103:20; Hebrews 1:7; Psalm 104:4). “Watcher angels” are mentioned in the book of Daniel (Daniel 4:13, 17, 23). Angels are often described as military “hosts” of the celestial armies (Jeremiah 5:14; 38:17; 44:7; Hosea 12:5). Other times angels are called “sons of the mighty” (Psalm 89:6) or “sons of God” (Job 2:1).
A few passages of Scripture describe angels as stars (Revelation 9:1; 12:4; Job 38:7–8; Daniel 8:10; Judges 5:20). The idea of stars may give us our best clue as to how many angels there are. If angels are like the stars in heaven, they are too many to count.
“And he said, The Lord came from Sinai, and rose up from Seir unto them; he shined forth from mount Paran, and he came with ten thousands of saints: from his right hand went a fiery law for them.” Deuteronomy 33:2