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Number

690

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

Abundant Number Harshad / Niven Smith Number Squarefree Year

Properties

Parity
Even
Digit count
3
Digit sum
15
Digital root
6
Palindrome
No
Divisor count
16
σ(n) — sum of divisors
1,728

Primality

Prime factorization: 2 × 3 × 5 × 23

Divisors & multiples

All divisors (16)
1 · 2 · 3 · 5 · 6 · 10 · 15 · 23 · 30 · 46 · 69 · 115 · 138 · 230 · 345 · 690
Aliquot sum (sum of proper divisors): 1,038
Factor pairs (a × b = 690)
1 × 690
2 × 345
3 × 230
5 × 138
6 × 115
10 × 69
15 × 46
23 × 30
First multiples
690 · 1,380 · 2,070 · 2,760 · 3,450 · 4,140 · 4,830 · 5,520 · 6,210 · 6,900

Representations

In words
six hundred ninety
Ordinal
690th
Roman numeral
DCXC
Binary
1010110010
Octal
1262
Hexadecimal
2B2

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 690, here are decompositions:

  • 7 + 683 = 690
  • 13 + 677 = 690
  • 17 + 673 = 690
  • 29 + 661 = 690
  • 31 + 659 = 690
  • 37 + 653 = 690
  • 43 + 647 = 690
  • 47 + 643 = 690

Showing the first eight; more decompositions exist.

Unicode codepoint
ʲ
U+02B2
Modifier letter (Lm)

UTF-8 encoding: CA B2 (2 bytes).

Lookup U+02B2 on Compart ↗ Lookup on FileFormat.Info ↗
Hex color
#0002B2
RGB(0, 2, 178)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.2.178.