Number
668
668 is a composite number, even, a calendar year.
Properties
- Parity
- Even
- Digit count
- 3
- Digit sum
- 20
- Digital root
- 2
- Palindrome
- No
- Divisor count
- 6
- σ(n) — sum of divisors
- 1,176
Primality
Prime factorization: 2 2 × 167
Divisors & multiples
Aliquot sum (sum of proper divisors):
508
Representations
- In words
- six hundred sixty-eight
- Ordinal
- 668th
- Roman numeral
- DCLXVIII
- Binary
- 1010011100
- Octal
- 1234
- Hexadecimal
- 29C
Also seen as
Goldbach decomposition
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 668, here are decompositions:
- 7 + 661 = 668
- 37 + 631 = 668
- 61 + 607 = 668
- 67 + 601 = 668
- 97 + 571 = 668
- 127 + 541 = 668
- 181 + 487 = 668
- 211 + 457 = 668
Showing the first eight; more decompositions exist.
Unicode codepoint
ʜ
U+029C
Lowercase letter (Ll)
UTF-8 encoding: CA 9C (2 bytes).
Hex color
#00029C
RGB(0, 2, 156)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.156.