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666 Six hundred and sixty six. The number before 667 and after 665. You will get to this number if you keep counting. Nothing but a number. also expressed as 1010011010 or 29A.
i saw 666 on my door oh god i'm so scared ! mamma mia!
by Xhamlliku October 29, 2004 Get a 666 mug for your brother-in-law Abdul.
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666 is an abundant number. It is the sum of the squares of the first seven prime numbers.

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).

I had no idea that the number 666 had any relavance to a legitimate mathmatical formula!
by Cortan May 23, 2006 Get the 666 neck gaiter and mug.