Then Goatnose raised his aforesaid left hand higher in the air than ever, extending all its five fingers and stretching them as wide as he could.

"Now," said Pantagruel, "he is informing us more positively, by giving us the sign of the quinary number. That means that you will certainly be married, and not only affiances, espoused, and married, but that, furthermore, you will cohabit and get on well with the job. Pythagoras called the quinary number the nuptial number, which indicated a wedding and the consummation of a marriage, being composed of the triad, which is the first odd and superfluous number, and of the dyad, which is the first even number. This signifies the males and female in copulation. Indeed at Rome, in the olden times, they would light five wax candles on a wedding day: and it was not permissible to light more, even at the marriage of the wealthiest, or fewer, even at the marriage of the very poorest. Moreover, in the olden days the pagans used to implore the assistance of five dieties, or one god for five good offices, on behalf of those about to be married: of Jupiter, the nuptial god; of Juno, who presided over the feast; of Venus the fair; of Pitho, the goddess of persuasion and eloquence, and of Diana, who presided over childbrith.

Tiers Livre, 20.35 ff

The Pythagoreans thought of numbers as embodying various basic concepts. The even numbers were thought of as female, and the odd numbers were thought of as male. Two specifically stood for woman, and three for man., perhaps because of the appearance of the male and female genitalia. Five, as the combination of two and three, stood for marriage.
The possession of unusual powers came to the number five because it alone embraces all things that are and seem to be. Consequently, this number designates at once all things in the higher and lower realms.

Macrobius

A human body has five big things sticking out, and the Pythagoreans sometimes identified five with the body or with health. A hand has five fingers. Followers of Pythagoras sometimes wore lucky five pointed stars, as did William Hitchcock when he was shot in the back. Children usually draw houses as irregular pentagons.

Five aquired a negative significance during the Middle Ages. Summoning up the devil required the drawing of a pentagram.

Quinarius numerus haid parvae est potentia, constat enim ex primo pari et primo impari, tanquam ex foemina et masculo: impar enim numerus mas est, par vero foemina [...] idcirco numerus connubii appellatur a Pythagoricis.

H.C. Agrippa, De occulta philosophia, 2.8

There are five essences, five parts of musical harmonies, five zones, five inhabitants of the world (plants, fishes, birds, animals, humans), and five senses. Pliny mentions five divine trees (12.2). See also Plutarch, Roman Questions, 1.1 (264 B)