number.wiki
Number

820

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

Abundant Number Happy Number Harshad / Niven Triangular Year

Properties

Parity
Even
Digit count
3
Digit sum
10
Digital root
1
Palindrome
No
Divisor count
12
σ(n) — sum of divisors
1,764

Primality

Prime factorization: 2 2 × 5 × 41

Divisors & multiples

All divisors (12)
1 · 2 · 4 · 5 · 10 · 20 · 41 · 82 · 164 · 205 · 410 · 820
Aliquot sum (sum of proper divisors): 944
Factor pairs (a × b = 820)
1 × 820
2 × 410
4 × 205
5 × 164
10 × 82
20 × 41
First multiples
820 · 1,640 · 2,460 · 3,280 · 4,100 · 4,920 · 5,740 · 6,560 · 7,380 · 8,200

Representations

In words
eight hundred twenty
Ordinal
820th
Roman numeral
DCCCXX
Binary
1100110100
Octal
1464
Hexadecimal
334

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 820, here are decompositions:

  • 11 + 809 = 820
  • 23 + 797 = 820
  • 47 + 773 = 820
  • 59 + 761 = 820
  • 101 + 719 = 820
  • 137 + 683 = 820
  • 167 + 653 = 820
  • 173 + 647 = 820

Showing the first eight; more decompositions exist.

Unicode codepoint
̴
U+0334
Non-spacing mark (Mn)

UTF-8 encoding: CC B4 (2 bytes).

Hex color
#000334
RGB(0, 3, 52)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.52.