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21,968

21,968 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.).
Deficient Number Odious Number Pernicious Number Recamán's Sequence

Properties

Parity
Even
Digit count
5
Digit sum
26
Digit product
864
Digital root
8
Palindrome
No
Bit width
15 bits
Reversed
86,912
Recamán's sequence
a(167,827) = 21,968
Square (n²)
482,593,024
Cube (n³)
10,601,603,551,232
Divisor count
10
σ(n) — sum of divisors
42,594
φ(n) — Euler's totient
10,976
Sum of prime factors
1,381

Primality

Prime factorization: 2 4 × 1373

Nearest primes: 21,961 (−7) · 21,977 (+9)

Divisors & multiples

All divisors (10)
1 · 2 · 4 · 8 · 16 · 1373 · 2746 · 5492 · 10984 (half) · 21968
Aliquot sum (sum of proper divisors): 20,626
Factor pairs (a × b = 21,968)
1 × 21968
2 × 10984
4 × 5492
8 × 2746
16 × 1373
First multiples
21,968 · 43,936 (double) · 65,904 · 87,872 · 109,840 · 131,808 · 153,776 · 175,744 · 197,712 · 219,680

Sums & aliquot sequence

As a sum of two squares: 8² + 148²
As consecutive integers: 671 + 672 + … + 702
Aliquot sequence: 21,968 20,626 10,316 7,744 9,147 3,053 115 29 1 0 — terminates at zero

Representations

In words
twenty-one thousand nine hundred sixty-eight
Ordinal
21968th
Binary
101010111010000
Octal
52720
Hexadecimal
0x55D0
Base64
VdA=
One's complement
43,567 (16-bit)
In other bases
ternary (3) 1010010122
quaternary (4) 11113100
quinary (5) 1200333
senary (6) 245412
septenary (7) 121022
nonary (9) 33118
undecimal (11) 15561
duodecimal (12) 10868
tridecimal (13) 9ccb
tetradecimal (14) 8012
pentadecimal (15) 6798

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵καϡξηʹ
Mayan (base 20)
𝋢·𝋮·𝋲·𝋨
Chinese
二萬一千九百六十八
Chinese (financial)
貳萬壹仟玖佰陸拾捌
In other modern scripts
Eastern Arabic ٢١٩٦٨ Devanagari २१९६८ Bengali ২১৯৬৮ Tamil ௨௧௯௬௮ Thai ๒๑๙๖๘ Tibetan ༢༡༩༦༨ Khmer ២១៩៦៨ Lao ໒໑໙໖໘ Burmese ၂၁၉၆၈

Digit at this position in famous constants

π — Pi (π)
Digit 21,968 = 6
e — Euler's number (e)
Digit 21,968 = 9
φ — Golden ratio (φ)
Digit 21,968 = 7
√2 — Pythagoras's (√2)
Digit 21,968 = 3
ln 2 — Natural log of 2
Digit 21,968 = 4
γ — Euler-Mascheroni (γ)
Digit 21,968 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21968, here are decompositions:

  • 7 + 21961 = 21968
  • 31 + 21937 = 21968
  • 97 + 21871 = 21968
  • 109 + 21859 = 21968
  • 127 + 21841 = 21968
  • 151 + 21817 = 21968
  • 181 + 21787 = 21968
  • 211 + 21757 = 21968

Showing the first eight; more decompositions exist.

Unicode codepoint
CJK Unified Ideograph-55D0
U+55D0
Other letter (Lo)

UTF-8 encoding: E5 97 90 (3 bytes).

Hex color
#0055D0
RGB(0, 85, 208)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.85.208.

Address
0.0.85.208
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.85.208

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

Position in π

The digit sequence 21968 first appears in π at position 66,314 of the decimal expansion (the 66,314ordinal-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.