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21,086

21,086 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.).
Arithmetic Number Deficient Number Evil Number Gapful Number Recamán's Sequence Sphenic Number Squarefree

Properties

Parity
Even
Digit count
5
Digit sum
17
Digit product
0
Digital root
8
Palindrome
No
Bit width
15 bits
Reversed
68,012
Recamán's sequence
a(41,667) = 21,086
Square (n²)
444,619,396
Cube (n³)
9,375,244,584,056
Divisor count
8
σ(n) — sum of divisors
34,104
φ(n) — Euler's totient
9,720
Sum of prime factors
826

Primality

Prime factorization: 2 × 13 × 811

Nearest primes: 21,067 (−19) · 21,089 (+3)

Divisors & multiples

All divisors (8)
1 · 2 · 13 · 26 · 811 · 1622 · 10543 (half) · 21086
Aliquot sum (sum of proper divisors): 13,018
Factor pairs (a × b = 21,086)
1 × 21086
2 × 10543
13 × 1622
26 × 811
First multiples
21,086 · 42,172 (double) · 63,258 · 84,344 · 105,430 · 126,516 · 147,602 · 168,688 · 189,774 · 210,860

Sums & aliquot sequence

As consecutive integers: 5,270 + 5,271 + 5,272 + 5,273 1,616 + 1,617 + … + 1,628 380 + 381 + … + 431
Aliquot sequence: 21,086 13,018 7,430 5,962 3,830 3,082 1,814 910 1,106 814 554 280 440 640 890 730 602 — unresolved within range

Representations

In words
twenty-one thousand eighty-six
Ordinal
21086th
Binary
101001001011110
Octal
51136
Hexadecimal
0x525E
Base64
Ul4=
One's complement
44,449 (16-bit)
In other bases
ternary (3) 1001220222
quaternary (4) 11021132
quinary (5) 1133321
senary (6) 241342
septenary (7) 115322
nonary (9) 31828
undecimal (11) 1492a
duodecimal (12) 10252
tridecimal (13) 97a0
tetradecimal (14) 7982
pentadecimal (15) 63ab

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵καπϛʹ
Mayan (base 20)
𝋢·𝋬·𝋮·𝋦
Chinese
二萬一千零八十六
Chinese (financial)
貳萬壹仟零捌拾陸
In other modern scripts
Eastern Arabic ٢١٠٨٦ Devanagari २१०८६ Bengali ২১০৮৬ Tamil ௨௧௦௮௬ Thai ๒๑๐๘๖ Tibetan ༢༡༠༨༦ Khmer ២១០៨៦ Lao ໒໑໐໘໖ Burmese ၂၁၀၈၆

Digit at this position in famous constants

π — Pi (π)
Digit 21,086 = 6
e — Euler's number (e)
Digit 21,086 = 1
φ — Golden ratio (φ)
Digit 21,086 = 1
√2 — Pythagoras's (√2)
Digit 21,086 = 8
ln 2 — Natural log of 2
Digit 21,086 = 4
γ — Euler-Mascheroni (γ)
Digit 21,086 = 1

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21086, here are decompositions:

  • 19 + 21067 = 21086
  • 67 + 21019 = 21086
  • 73 + 21013 = 21086
  • 103 + 20983 = 21086
  • 127 + 20959 = 21086
  • 139 + 20947 = 21086
  • 157 + 20929 = 21086
  • 199 + 20887 = 21086

Showing the first eight; more decompositions exist.

Unicode codepoint
CJK Unified Ideograph-525E
U+525E
Other letter (Lo)

UTF-8 encoding: E5 89 9E (3 bytes).

Hex color
#00525E
RGB(0, 82, 94)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.94.

Address
0.0.82.94
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.94

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Position in π

The digit sequence 21086 first appears in π at position 121,547 of the decimal expansion (the 121,547ordinal-suffix:th digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.