Philo on the Number Six

Among numbers by the laws of nature the most suitable to productivity is six...It is the first perfect number, being equal to the product of its factors, as well as made up of the sum of them...It is in its nature both male and female, and is the result of the distinctive power of either. For among things that are it is the odd that is male, and the even female.- Philo of Alexandria, De opificio mundi, ch. 13 (tr. LCL)