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
Numerals in Unicode acrophonic numerals because all of the symbols used derive from the first letters of the words that the symbols represent: 'one', 'five', 'ten', 'hundred', 'thousand' and 'ten thousand'. See Greek numerals and acrophony. Roman numerals are a numeral system originating in ancient Rome, adapted from Etruscan numerals. The system used in classical antiquity was slightly modified in the Middle Ages to produce the system we use today. It is based on certain letters which are given values as numerals. Roman numerals are commonly used today in numbered lists (in outline format), clockfaces, pages preceding the main body of a book,