Modern numerology reduces seventy-nine to seven and reads it, like all numbers resolving to seven, as a call to analysis and inner enquiry, the seven approached through a seven of the tens and a nine of completion. This reductive reading is the only symbolic account the number attracts. Seventy-nine is best described as a prime without tradition, sourceable only through the standard reduction of modern numerology.
The genuine Pythagorean number philosophy that this modern chart borrows its name from left no writings of its own: Pythagoras and his early followers taught only by mouth, and what survives of their number theory comes instead through Nicomachus of Gerasa, whose Introduction to Arithmetic of the first century CE became the standard authority for a thousand years, and through Iamblichus, who drew on Nicomachus two centuries later; neither wrote anything resembling a name-and-birthdate numerology.
Nicomachus's own arithmetic sorted whole numbers into deficient, perfect and abundant by comparing them with the sum of their own divisors, a genuinely ancient classification that has nothing to do with the letter charts later numerologists built; the modern system that assigns meaning to digit sums is a distinct, twentieth-century construction that happens to borrow the Pythagorean name.