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21,120

21,120 is a composite number, even.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).
Abundant Number Happy Number Harshad / Niven

Properties

Parity
Even
Digit count
5
Digit sum
6
Digital root
6
Palindrome
No
Divisor count
64
σ(n) — sum of divisors
73,440

Primality

Prime factorization: 2 7 × 3 × 5 × 11

Divisors & multiples

All divisors (64)
1 · 2 · 3 · 4 · 5 · 6 · 8 · 10 · 11 · 12 · 15 · 16 · 20 · 22 · 24 · 30 · 32 · 33 · 40 · 44 · 48 · 55 · 60 · 64 · 66 · 80 · 88 · 96 · 110 · 120 · 128 · 132 · 160 · 165 · 176 · 192 · 220 · 240 · 264 · 320 · 330 · 352 · 384 · 440 · 480 · 528 · 640 · 660 · 704 · 880 · 960 · 1056 · 1320 · 1408 · 1760 · 1920 · 2112 · 2640 · 3520 · 4224 · 5280 · 7040 · 10560 · 21120
Aliquot sum (sum of proper divisors): 52,320
Factor pairs (a × b = 21,120)
1 × 21120
2 × 10560
3 × 7040
4 × 5280
5 × 4224
6 × 3520
8 × 2640
10 × 2112
11 × 1920
12 × 1760
15 × 1408
16 × 1320
20 × 1056
22 × 960
24 × 880
30 × 704
32 × 660
33 × 640
40 × 528
44 × 480
48 × 440
55 × 384
60 × 352
64 × 330
66 × 320
80 × 264
88 × 240
96 × 220
110 × 192
120 × 176
128 × 165
132 × 160
First multiples
21,120 · 42,240 · 63,360 · 84,480 · 105,600 · 126,720 · 147,840 · 168,960 · 190,080 · 211,200

Representations

In words
twenty-one thousand one hundred twenty
Ordinal
21120th
Binary
101001010000000
Octal
51200
Hexadecimal
5280

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21120, here are decompositions:

  • 13 + 21107 = 21120
  • 19 + 21101 = 21120
  • 31 + 21089 = 21120
  • 53 + 21067 = 21120
  • 59 + 21061 = 21120
  • 61 + 21059 = 21120
  • 89 + 21031 = 21120
  • 97 + 21023 = 21120

Showing the first eight; more decompositions exist.

Unicode codepoint
U+5280
Other letter (Lo)

UTF-8 encoding: E5 8A 80 (3 bytes).

Hex color
#005280
RGB(0, 82, 128)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.128.