What does “666” mean?

There were at least three people who claimed to be Nero between ad69–96 and, according to St Augustine, there was a belief as late as the fifth century ad that Nero would return as the Antichrist (De civ. d. 20.19.3) (Paul A. Gallivan, “The False Neros: A Re-Examination”, Historia 22 (1973).

1. “Nero Caesar” transliterated into the Hebrew from the Greek (Neron Kaiser) adds up to exactly 666 in Hebrew. N=50, R=200, W=6, N=50 plus Q=100, S=60, R=200 totals 666. This spelling of Nero Caesar was found in the discovery of an Aramaic document in Wadi Murabba`at (BASOR 170, 65). The Latin form of “Nero Caesar” when transliterated into Hebrew adds up to 616. This most likely explains the textual variant in Revelation 13:18 with the number 616. It should also be noted that the Greek word for “Beast” when transliterated back into Hebrew adds up to 666. Ancient writers referred to Nero as a “beast” (See Philostratus Vit. Apoll. 4.38; Sib. Or. 5.343; 8.157).”
2. BibleUnboxed video: https://youtu.be/5PIC0oYV2AY Abibledarkly video: https://youtu.be/xo_zAw1EYqs Religion for breakfasts video: https://youtu.be/7-PqevqQEQ4 Dan Mcclellans video: https://youtu.be/cH_yITaobYk (This also talks about the right hand and forehead aspect of it as well). Dan Mcclellans Podcast episode: https://youtu.be/Bs02oP4kQbM

1. In this case, the number is a good match for the emperor Nero, who reigned from 54 to 68 CE. His name in Greek, written using Hebrew letters, adds up to 666 as shown below: Nerōn Kaisar = נרון קסר (NRWN QSR) = 666

1. Some of our oldest manuscripts actually have the much-less-fearful number 616 instead of 666. This supports the identification with Nero, since spelling his name in Latin (Nerō Kaisar) rather than Greek will produce that exact number. That bit about the Beast whose mortal wound was healed is probably a reference to the Nero Redivivus legend of the late first century. It was commonly believed, after Nero’s apparent suicide in 68, that the he was still alive in the East somewhere and would return again to restore or destroy Rome. In fact, at least three pretenders appeared over the next two decades, impersonating Nero and leading rebellions that were swiftly crushed. The second beast, which makes the people worship the first beast, might be the priesthood and government officials that served the imperial cult (a common view among scholars) or perhaps the leading families of Asia Minor who supported the cult and controlled its offices (the view of Adela Yarbro Collins) (Adela Yarbro Collins, “ ‘What the Spirit Says to the Churches’: Preaching the Apocalypse,” QR 4 (1984): 82. Cited in Barr, ed., Reading the book of Revelation: a resource for students (RBS 44, 2003): 63.).