number.wiki
Number

18,311

18,311 is a prime, odd.

18,311 (eighteen thousand three hundred eleven) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x4787.

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

Interestingness

Properties

Parity
Odd
Digit count
5
Digit sum
14
Digit product
24
Digital root
5
Palindrome
No
Bit width
15 bits
Reversed
11,381
Recamán's sequence
a(13,846) = 18,311
Square (n²)
335,292,721
Cube (n³)
6,139,545,014,231
Divisor count
2
σ(n) — sum of divisors
18,312
φ(n) — Euler's totient
18,310

Primality

18,311 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 18311
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 18,311)
1 × 18311
First multiples
18,311 · 36,622 (double) · 54,933 · 73,244 · 91,555 · 109,866 · 128,177 · 146,488 · 164,799 · 183,110

Sums & aliquot sequence

As consecutive integers: 9,155 + 9,156

Continued fraction of √n

√18,311 = [135; (3, 6, 1, 53, 3, 1, 3, 1, 5, 10, 1, 1, 1, 7, 3, 3, 2, 1, 1, 2, 1, 2, 2, 6, …)]

Representations

In words
eighteen thousand three hundred eleven
Ordinal
18311th
Binary
100011110000111
Octal
43607
Hexadecimal
0x4787
Base64
R4c=
One's complement
47,224 (16-bit)
Scientific notation
1.8311 × 10⁴
As a duration
18,311 s = 5 hours, 5 minutes, 11 seconds
In other bases
ternary (3) 221010012
quaternary (4) 10132013
quinary (5) 1041221
senary (6) 220435
septenary (7) 104246
nonary (9) 27105
undecimal (11) 12837
duodecimal (12) a71b
tridecimal (13) 8447
tetradecimal (14) 695d
pentadecimal (15) 565b

As an angle

18,311° = 50 × 360° + 311°
311° ≈ 5.428 rad
Compass bearing: NW (northwest)

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹 𒌋𒁹
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓎆𓏺
Greek (Milesian)
͵ιητιαʹ
Mayan (base 20)
𝋢·𝋥·𝋯·𝋫
Chinese
一萬八千三百一十一
Chinese (financial)
壹萬捌仟參佰壹拾壹
In other modern scripts
Eastern Arabic ١٨٣١١ Devanagari १८३११ Bengali ১৮৩১১ Tamil ௧௮௩௧௧ Thai ๑๘๓๑๑ Tibetan ༡༨༣༡༡ Khmer ១៨៣១១ Lao ໑໘໓໑໑ Burmese ၁၈၃၁၁

Digit at this position in famous constants

π — Pi (π)
Digit 18,311 = 2
e — Euler's number (e)
Digit 18,311 = 6
φ — Golden ratio (φ)
Digit 18,311 = 3
√2 — Pythagoras's (√2)
Digit 18,311 = 8
ln 2 — Natural log of 2
Digit 18,311 = 0
γ — Euler-Mascheroni (γ)
Digit 18,311 = 6

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 18,307 (gap of 4)
  • Next prime: 18,313 (gap of 2)

Pair status: twin with 18313, cousin with 18307.

Unicode codepoint
CJK Unified Ideograph-4787
U+4787
Other letter (Lo)

UTF-8 encoding: E4 9E 87 (3 bytes).

Hex color
#004787
RGB(0, 71, 135)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.71.135.

Address
0.0.71.135
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.71.135

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

Musical pitch

Heard as a frequency, 18,311 Hz is closest to:

  • Concert pitch (A4 = 440 Hz): D10 (18794.5 Hz, -45¢ — about midway to C♯10)
  • Scientific pitch (C4 = 256 Hz): D10 (18390.4 Hz, -7¢)
  • Baroque pitch (A4 = 415 Hz): D♯10 (18780.8 Hz, -44¢)
Position in π

The digit sequence 18311 first appears in π at position 54,900 of the decimal expansion (the 54,900ordinal-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.