666 is the number that preceeds 665 and proceeds 667. It is known as the illuminati or Number of the Beast.

The prime factorization of the number 666 is .

666 is the sum of the first 36 natural numbers . It is also the sum of the squares of the first 7 primes (ie.)

When you flip over 666, you get 999, the biggest 3 digit number.

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