This has the implication for males that a lust for sex will turn you into an evil bastard just like the rest of us.
It is interesting that 666 has been around longer than the microscope and knowledge of sperm!
Since 36 is both square and triangular, 666 is the sixth number of the form n2(n2 + 1) / 2 (triangular squares) and the eighth number of the form n(n + 1)(n2 + n + 2) / 8 (doubly triangular numbers.)
There is no number whose value of Euler's totient function ö is 666, making it a nontotient.
The harmonic mean of the digits of 666 is an integer: 3/(1/6 + 1/6 + 1/6) = 6. 666 is the 54th number with this property.
In base 10, 666 is a palindromic number, a repdigit and a Smith number. A prime reciprocal magic square based on 1/149 in base 10 has a magic total of 666.
The Roman numeral representation of the number 666 (DCLXVI) uses once each the Roman numeral symbols with values under 1,000, and they occur in exact reverse order of their respective values (D = 500, C = 100, L = 50, X = 10, V = 5, I = 1).
Let he who hath understanding reckon the number of the beast for it is a human number.
It's number is six hundred and sixty six.
-Revelations chapter 13, Verse 18. As said in "The number of the beast" by Iron Maiden