Number

666

666 — The Number of the Beast

666 is a composite number, even, a calendar year.

Six hundred sixty-six is the Number of the Beast in the Book of Revelation. Mathematically, it is the sum of the squares of the first seven primes ((2^{2 + 3}2 + 5^{2 + 7}2 + 11^{2 + 13}2 + 17^2)) and is a triangular number ((T_{36})).

Sources https://en.wikipedia.org/wiki/Number_of_the_beast

Abundant Number Curated Harshad / Niven Palindrome Repdigit Smith Number Triangular

Properties

Parity: Even
Digit count: 3
Digit sum: 18
Digital root: 9
Palindrome: Yes
Divisor count: 12
σ(n) — sum of divisors: 1,482

Primality

Prime factorization: 2 × 3 ² × 37

Divisors & multiples

All divisors (12)

1 · 2 · 3 · 6 · 9 · 18 · 37 · 74 · 111 · 222 · 333 · 666

Aliquot sum (sum of proper divisors): 816

Factor pairs (a × b = 666)

1 × 666

2 × 333

3 × 222

6 × 111

9 × 74

18 × 37

First multiples

666 · 1,332 · 1,998 · 2,664 · 3,330 · 3,996 · 4,662 · 5,328 · 5,994 · 6,660

Representations

In words: six hundred sixty-six
Ordinal: 666th
Roman numeral: DCLXVI
Binary: 1010011010
Octal: 1232
Hexadecimal: 29A

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 666, here are decompositions:

5 + 661 = 666
7 + 659 = 666
13 + 653 = 666
19 + 647 = 666
23 + 643 = 666
47 + 619 = 666
53 + 613 = 666
59 + 607 = 666

Showing the first eight; more decompositions exist.

Unicode codepoint

U+029A

Lowercase letter (Ll)

UTF-8 encoding: CA 9A (2 bytes).

Lookup U+029A on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00029A

RGB(0, 2, 154)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.154.