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Number

21,143

21,143 is a prime, odd.

21,143 (twenty-one thousand one hundred forty-three) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x5297.

Arithmetic Number Chen Prime Cousin Prime Cube-Free Deficient Number Evil Number Happy Number Prime Recamán's Sequence Sexy Prime Squarefree

Interestingness

Properties

Parity
Odd
Digit count
5
Digit sum
11
Digit product
24
Digital root
2
Palindrome
No
Bit width
15 bits
Reversed
34,112
Recamán's sequence
a(41,553) = 21,143
Square (n²)
447,026,449
Cube (n³)
9,451,480,211,207
Divisor count
2
σ(n) — sum of divisors
21,144
φ(n) — Euler's totient
21,142

Primality

21,143 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21143
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,143)
1 × 21143
First multiples
21,143 · 42,286 (double) · 63,429 · 84,572 · 105,715 · 126,858 · 148,001 · 169,144 · 190,287 · 211,430

Sums & aliquot sequence

As consecutive integers: 10,571 + 10,572

Continued fraction of √n

√21,143 = [145; (2, 2, 5, 1, 11, 1, 4, 145, 4, 1, 11, 1, 5, 2, 2, 290)]

Period length 16 — the block in parentheses repeats forever.

Representations

In words
twenty-one thousand one hundred forty-three
Ordinal
21143rd
Binary
101001010010111
Octal
51227
Hexadecimal
0x5297
Base64
Upc=
One's complement
44,392 (16-bit)
Scientific notation
2.1143 × 10⁴
As a duration
21,143 s = 5 hours, 52 minutes, 23 seconds
In other bases
ternary (3) 1002000002
quaternary (4) 11022113
quinary (5) 1134033
senary (6) 241515
septenary (7) 115433
nonary (9) 32002
undecimal (11) 14981
duodecimal (12) 1029b
tridecimal (13) 9815
tetradecimal (14) 79c3
pentadecimal (15) 63e8

As an angle

21,143° = 58 × 360° + 263°
263° ≈ 4.59 rad
Compass bearing: W (west)

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹 𒌋𒌋𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺
Greek (Milesian)
͵καρμγʹ
Mayan (base 20)
𝋢·𝋬·𝋱·𝋣
Chinese
二萬一千一百四十三
Chinese (financial)
貳萬壹仟壹佰肆拾參
In other modern scripts
Eastern Arabic ٢١١٤٣ Devanagari २११४३ Bengali ২১১৪৩ Tamil ௨௧௧௪௩ Thai ๒๑๑๔๓ Tibetan ༢༡༡༤༣ Khmer ២១១៤៣ Lao ໒໑໑໔໓ Burmese ၂၁၁၄၃

Digit at this position in famous constants

π — Pi (π)
Digit 21,143 = 7
e — Euler's number (e)
Digit 21,143 = 0
φ — Golden ratio (φ)
Digit 21,143 = 9
√2 — Pythagoras's (√2)
Digit 21,143 = 6
ln 2 — Natural log of 2
Digit 21,143 = 0
γ — Euler-Mascheroni (γ)
Digit 21,143 = 8

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,139 (gap of 4)
  • Next prime: 21,149 (gap of 6)

Pair status: cousin with 21139, sexy with 21149.

Unicode codepoint
CJK Unified Ideograph-5297
U+5297
Other letter (Lo)

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

Hex color
#005297
RGB(0, 82, 151)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.151.

Address
0.0.82.151
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.151

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

Position in π

The digit sequence 21143 first appears in π at position 62,417 of the decimal expansion (the 62,417ordinal-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.

Related reading

  • Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
  • Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.