number.wiki
Number

18,401

18,401 is a prime, odd.

Arithmetic Number Cousin Prime Deficient Number Evil Number Happy Number Prime Pythagorean Prime Recamán's Sequence Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
14
Digit product
0
Digital root
5
Palindrome
No
Bit width
15 bits
Reversed
10,481
Recamán's sequence
a(8,642) = 18,401
Square (n²)
338,596,801
Cube (n³)
6,230,519,735,201
Divisor count
2
σ(n) — sum of divisors
18,402
φ(n) — Euler's totient
18,400

Primality

18,401 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 18401
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 18,401)
1 × 18401
First multiples
18,401 · 36,802 (double) · 55,203 · 73,604 · 92,005 · 110,406 · 128,807 · 147,208 · 165,609 · 184,010

Sums & aliquot sequence

As a sum of two squares: 55² + 124²
As consecutive integers: 9,200 + 9,201

Representations

In words
eighteen thousand four hundred one
Ordinal
18401st
Binary
100011111100001
Octal
43741
Hexadecimal
0x47E1
Base64
R+E=
One's complement
47,134 (16-bit)
In other bases
ternary (3) 221020112
quaternary (4) 10133201
quinary (5) 1042101
senary (6) 221105
septenary (7) 104435
nonary (9) 27215
undecimal (11) 12909
duodecimal (12) a795
tridecimal (13) 84b6
tetradecimal (14) 69c5
pentadecimal (15) 56bb

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓏺
Greek (Milesian)
͵ιηυαʹ
Mayan (base 20)
𝋢·𝋦·𝋠·𝋡
Chinese
一萬八千四百零一
Chinese (financial)
壹萬捌仟肆佰零壹
In other modern scripts
Eastern Arabic ١٨٤٠١ Devanagari १८४०१ Bengali ১৮৪০১ Tamil ௧௮௪௦௧ Thai ๑๘๔๐๑ Tibetan ༡༨༤༠༡ Khmer ១៨៤០១ Lao ໑໘໔໐໑ Burmese ၁၈၄၀၁

Digit at this position in famous constants

π — Pi (π)
Digit 18,401 = 2
e — Euler's number (e)
Digit 18,401 = 2
φ — Golden ratio (φ)
Digit 18,401 = 7
√2 — Pythagoras's (√2)
Digit 18,401 = 9
ln 2 — Natural log of 2
Digit 18,401 = 4
γ — Euler-Mascheroni (γ)
Digit 18,401 = 8

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 18,397 (gap of 4)
  • Next prime: 18,413 (gap of 12)

Pair status: cousin with 18397.

Unicode codepoint
CJK Unified Ideograph-47E1
U+47E1
Other letter (Lo)

UTF-8 encoding: E4 9F A1 (3 bytes).

Hex color
#0047E1
RGB(0, 71, 225)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.71.225.

Address
0.0.71.225
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.71.225

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

Position in π

The digit sequence 18401 first appears in π at position 86,905 of the decimal expansion (the 86,905ordinal-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.