number.wiki
Number

680

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

Abundant Number Happy Number Tetrahedral Year

Properties

Parity
Even
Digit count
3
Digit sum
14
Digital root
5
Palindrome
No
Divisor count
16
σ(n) — sum of divisors
1,620

Primality

Prime factorization: 2 3 × 5 × 17

Divisors & multiples

All divisors (16)
1 · 2 · 4 · 5 · 8 · 10 · 17 · 20 · 34 · 40 · 68 · 85 · 136 · 170 · 340 · 680
Aliquot sum (sum of proper divisors): 940
Factor pairs (a × b = 680)
1 × 680
2 × 340
4 × 170
5 × 136
8 × 85
10 × 68
17 × 40
20 × 34
First multiples
680 · 1,360 · 2,040 · 2,720 · 3,400 · 4,080 · 4,760 · 5,440 · 6,120 · 6,800

Representations

In words
six hundred eighty
Ordinal
680th
Roman numeral
DCLXXX
Binary
1010101000
Octal
1250
Hexadecimal
2A8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 680, here are decompositions:

  • 3 + 677 = 680
  • 7 + 673 = 680
  • 19 + 661 = 680
  • 37 + 643 = 680
  • 61 + 619 = 680
  • 67 + 613 = 680
  • 73 + 607 = 680
  • 79 + 601 = 680

Showing the first eight; more decompositions exist.

Unicode codepoint
ʨ
U+02A8
Lowercase letter (Ll)

UTF-8 encoding: CA A8 (2 bytes).

Hex color
#0002A8
RGB(0, 2, 168)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.168.