Live analysis
21,000
21,000 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.).
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 3
- Digital root
- 3
- Palindrome
- No
- Divisor count
- 64
- σ(n) — sum of divisors
- 74,880
Primality
Prime factorization: 2 3 × 3 × 5 3 × 7
Divisors & multiples
All divisors (64)
1
· 2
· 3
· 4
· 5
· 6
· 7
· 8
· 10
· 12
· 14
· 15
· 20
· 21
· 24
· 25
· 28
· 30
· 35
· 40
· 42
· 50
· 56
· 60
· 70
· 75
· 84
· 100
· 105
· 120
· 125
· 140
· 150
· 168
· 175
· 200
· 210
· 250
· 280
· 300
· 350
· 375
· 420
· 500
· 525
· 600
· 700
· 750
· 840
· 875
· 1000
· 1050
· 1400
· 1500
· 1750
· 2100
· 2625
· 3000
· 3500
· 4200
· 5250
· 7000
· 10500
· 21000
Aliquot sum (sum of proper divisors):
53,880
Factor pairs (a × b = 21,000)
First multiples
21,000
· 42,000
· 63,000
· 84,000
· 105,000
· 126,000
· 147,000
· 168,000
· 189,000
· 210,000
Representations
- In words
- twenty-one thousand
- Ordinal
- 21000th
- Binary
- 101001000001000
- Octal
- 51010
- Hexadecimal
- 5208
Also seen as
Goldbach decomposition
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21000, here are decompositions:
- 17 + 20983 = 21000
- 19 + 20981 = 21000
- 37 + 20963 = 21000
- 41 + 20959 = 21000
- 53 + 20947 = 21000
- 61 + 20939 = 21000
- 71 + 20929 = 21000
- 79 + 20921 = 21000
Showing the first eight; more decompositions exist.
Unicode codepoint
刈
U+5208
Other letter (Lo)
UTF-8 encoding: E5 88 88 (3 bytes).
Hex color
#005208
RGB(0, 82, 8)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.8.