Notice that 1/7 = 0,142857142857142857 ...

This 6x6 magic square of order 6 has magic constant 111.
The sum of numbers in any row, column, or diagonal is always 111.

6 x 111 = 666 and this is the number of the beast and is often associated with the devil.

666 is the sum of the first 36 natural numbers (1 + 2 + 3 + ... + 34 + 35 + 36 = 666).

Also, 666 is the sum of squares of first seven primes: 2² + 3² + 5² + 7² + 11² + 13² + 17².

The Roman numeral for 666, DCLXVI, has exactly one occurrence of all symbols
whose value is less than 1000 in decreasing order (D = 500, C = 100, L = 50, X = 10, V = 5, I = 1).