Eighty-five is five times seventeen and reduces to thirteen and then four. It is one of the integers in the eighties without traditional religious symbolism; the older systems did not develop it. What can honestly be said of it is structural only, and structure is not lore.
Eighty-five factors as 5 x 17 and carries 4 divisors in all. Summing its proper divisors gives only 23, short of the number itself, which places it among the deficient numbers in the same classical scheme.
The whole apparatus of digit-reduction numerology is a twentieth-century invention rather than an inheritance from antiquity. Mrs. L. Dow Balliett published the first systematic version, The Philosophy of Numbers, in 1908, fixing the letter-to-number chart still used today and ruling that eleven and twenty-two must stand as master numbers rather than reduce further; her colleague, the physician Julia Seton, is credited with coining the word numerology itself around 1912.
A separate and older-claimed system, generally called Chaldean numerology, assigns letters to digits irregularly rather than in Balliett's repeating one-to-nine sequence, and deliberately omits nine from the chart as too sacred to attach to an ordinary letter; its popular billing as a genuinely ancient Babylonian system rests on assertion rather than on any textual evidence that has been traced back that far.