Ninety-three is three times thirty-one and reduces to twelve and then three. Its one developed symbolism is modern and specific: in the system of Thelema founded by Aleister Crowley, ninety-three is the central number, because the two Greek words at the heart of the creed, thelema, will, and agape, love, each total ninety-three by isopsephy, the Greek equivalent of gematria. The equality is taken to mean that Do what thou wilt and Love are one law, and Thelemites greet one another with the number, opening a letter with ninety-three and closing with ninety-three ninety-three slash ninety-three.
In chemistry, ninety-three is the atomic number of neptunium, named after the planet Neptune in the sequence begun when uranium was named for Uranus; it was the first transuranium element ever synthesised, in 1940.
Ninety-three factors as 3 x 31 and carries 4 divisors in all. Summing its proper divisors gives only 35, 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.