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 numeral analysis related to or derived from the common practice period, Roman numerals are frequently used to designate scale degrees as well as the chords built on them. In some contexts, arabic numerals with carets are used to designate scale degrees (); theory related to or derived from jazz or modern popular music may use Roman numerals or arabic numbers (1, 2, 3, etc...) to represent scale degrees "(See also diatonic function)". In some contexts an arabic number, or careted number, may refer also to a chord built upon that scale degree. For example, or 1 may both refer to the chord