Old news (Vicarius Filii Dei = 666)

From Wikipedia:

The earliest extant record of a Protestant writer on this subject and addressing the phrase Vicarius Filii Dei is Andreas Helwig in 1612. In his work Antichristus Romanus he took fifteen titles in Hebrew, Greek, and Latin and computed their numerical equivalents in those languages, arriving at the number 666 mentioned in the Book of Revelation. Out of all these titles, he preferred to single out Vicarius Filii Dei, used in the Donation of Constantine, for the reason that it met "all the conditions which [Cardinal] Bellarmine had thus far demanded." Besides being in Latin, the title was "not offensive or vile," but rather was "honorable to this very one." (The sum works as follows: VICARIVS FILII DEI = 5+1+100+1+5+1+50+1+1+500+1 = 666, where 'U' is taken as 'V', see U for interchangeability reasoning).