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Number

18,121

18,121 is a prime, odd.

Arithmetic Number Deficient Number Odious Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
5
Digit sum
13
Digit product
16
Digital root
4
Palindrome
No
Bit width
15 bits
Reversed
12,181
Recamán's sequence
a(15,602) = 18,121
Square (n²)
328,370,641
Cube (n³)
5,950,404,385,561
Divisor count
2
σ(n) — sum of divisors
18,122
φ(n) — Euler's totient
18,120

Primality

18,121 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 18121
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 18,121)
1 × 18121
First multiples
18,121 · 36,242 (double) · 54,363 · 72,484 · 90,605 · 108,726 · 126,847 · 144,968 · 163,089 · 181,210

Sums & aliquot sequence

As a sum of two squares: 61² + 120²
As consecutive integers: 9,060 + 9,061

Representations

In words
eighteen thousand one hundred twenty-one
Ordinal
18121st
Binary
100011011001001
Octal
43311
Hexadecimal
0x46C9
Base64
Rsk=
One's complement
47,414 (16-bit)
In other bases
ternary (3) 220212011
quaternary (4) 10123021
quinary (5) 1034441
senary (6) 215521
septenary (7) 103555
nonary (9) 26764
undecimal (11) 12684
duodecimal (12) a5a1
tridecimal (13) 832c
tetradecimal (14) 6865
pentadecimal (15) 5581

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒁹𒁹 𒁹
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓎆𓎆𓏺
Greek (Milesian)
͵ιηρκαʹ
Mayan (base 20)
𝋢·𝋥·𝋦·𝋡
Chinese
一萬八千一百二十一
Chinese (financial)
壹萬捌仟壹佰貳拾壹
In other modern scripts
Eastern Arabic ١٨١٢١ Devanagari १८१२१ Bengali ১৮১২১ Tamil ௧௮௧௨௧ Thai ๑๘๑๒๑ Tibetan ༡༨༡༢༡ Khmer ១៨១២១ Lao ໑໘໑໒໑ Burmese ၁၈၁၂၁

Digit at this position in famous constants

π — Pi (π)
Digit 18,121 = 3
e — Euler's number (e)
Digit 18,121 = 7
φ — Golden ratio (φ)
Digit 18,121 = 2
√2 — Pythagoras's (√2)
Digit 18,121 = 5
ln 2 — Natural log of 2
Digit 18,121 = 5
γ — Euler-Mascheroni (γ)
Digit 18,121 = 9

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 18,119 (gap of 2)
  • Next prime: 18,127 (gap of 6)

Pair status: twin with 18119, sexy with 18127.

Unicode codepoint
CJK Unified Ideograph-46C9
U+46C9
Other letter (Lo)

UTF-8 encoding: E4 9B 89 (3 bytes).

Hex color
#0046C9
RGB(0, 70, 201)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.70.201.

Address
0.0.70.201
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.70.201

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

Position in π

The digit sequence 18121 first appears in π at position 297,024 of the decimal expansion (the 297,024ordinal-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.