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
Prehistoric numerals Prehistoric numerals Counting in prehistory was first assisted by using body parts, primarily the fingers. This is reflected in the etymology of certain number names, such as in the names of "ten" and "hundred" in the Proto-Indo-European numerals, both containing the root *"dḱ" also seen in the word for "finger" (Latin "digitus", cognate to English "toe"). Early systems of counting using tally marks appear in the Upper Paleolithic. The first more complex systems develop in the Ancient Near East together with the development of early writing out of proto-writing systems. Numerals originally developed from the use of tally marks as