Egyptian Hermes (i.e. Thoth) is the creator of literacy and therefore numeracy (Diodorus 1.16).
It was by Hermes, for instance, according to them, that the common language of mankind was first further articulated, and that many objects which were still nameless received an appellation, that the alphabet was invented, and that ordinances regarding the honours and offerings due to the gods were duly established; he was the first also to observe the orderly arrangement of the stars and the harmony of the musical sounds and their nature, to establish a wrestling school, and to give thought to the rhythmical movement of the human body and its proper development. He also made a lyre and gave it three strings, imitating the seasons of the year; for he adopted three tones, a high, a low, and a medium; the high from the summer, the low from the winter, and the medium from the spring.
Diodorus via Lacus Curtius
We must remember that Greek numbers are merely letters (rarely otherwise) that correspond to a numerical value.