According to Mario Livio, 6 is the lowest perfect number.
Pythagoras and his followers spent their lives riffing about numbers and geometry. They decided that a perfect number was a number that was the sum of its factors. 1 x 2 x 3 is the same as 1 + 2 + 3. In case you were interested, the next one is 28.
Exactly. They didn’t realize that they should have been working on calculus instead of messing around creating and polishing stuff that no one needed or cared about.