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
English numerals suffixes to produce the empty numbers "umpteen" and "umpty": it is of uncertain origin. There is a noticeable absence of an empty number in the hundreds range. Usage of empty numbers: See also Placeholder name. English numerals English number words include numerals and various words derived from them, as well as a large number of words borrowed from other languages. Cardinal numbers refer to the size of a group. In English, these words are numerals. If a number is in the range 21 to 99, and the second digit is not zero, one typically writes the number as two words