666 (number) on 1/149 in base 10 has a magic total of 666. The prime factorization of 666 is 2 • 3 • 37. Also, 666 is the sum of squares of first seven primes: formula_2 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). In the Textus Receptus manuscripts of the New Testament, the Book of Revelation () cryptically asserts 666 to be "man's number" or "the number of a
Roman numerals ordinary Roman numerals - but instead of , or we use "barred" notation to express the thousands - which greatly expands the range of numbers expressible. For instance: If this were ever to be applied consistently in our own times - then the main difficulty would be what to do with "" - one way would be to do away with "" altogether, except perhaps for ' (=900) - thus rendering ' as ' - or alternatively to retain "" in its current usage, with the barred numerals starting at ' (=4,000). Retaining "" would permit our numerals to run