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Number

21,023

21,023 is a prime, odd.

Arithmetic Number Cousin Prime Deficient Number Evil Number Prime Recamán's Sequence Self Number Sexy Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
8
Digit product
0
Digital root
8
Palindrome
No
Bit width
15 bits
Reversed
32,012
Recamán's sequence
a(41,793) = 21,023
Square (n²)
441,966,529
Cube (n³)
9,291,462,339,167
Divisor count
2
σ(n) — sum of divisors
21,024
φ(n) — Euler's totient
21,022

Primality

21,023 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21023
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,023)
1 × 21023
First multiples
21,023 · 42,046 (double) · 63,069 · 84,092 · 105,115 · 126,138 · 147,161 · 168,184 · 189,207 · 210,230

Sums & aliquot sequence

As consecutive integers: 10,511 + 10,512

Representations

In words
twenty-one thousand twenty-three
Ordinal
21023rd
Binary
101001000011111
Octal
51037
Hexadecimal
0x521F
Base64
Uh8=
One's complement
44,512 (16-bit)
In other bases
ternary (3) 1001211122
quaternary (4) 11020133
quinary (5) 1133043
senary (6) 241155
septenary (7) 115202
nonary (9) 31748
undecimal (11) 14882
duodecimal (12) 101bb
tridecimal (13) 9752
tetradecimal (14) 7939
pentadecimal (15) 6368

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒌋𒌋𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓎆𓎆𓏺𓏺𓏺
Greek (Milesian)
͵κακγʹ
Mayan (base 20)
𝋢·𝋬·𝋫·𝋣
Chinese
二萬一千零二十三
Chinese (financial)
貳萬壹仟零貳拾參
In other modern scripts
Eastern Arabic ٢١٠٢٣ Devanagari २१०२३ Bengali ২১০২৩ Tamil ௨௧௦௨௩ Thai ๒๑๐๒๓ Tibetan ༢༡༠༢༣ Khmer ២១០២៣ Lao ໒໑໐໒໓ Burmese ၂၁၀၂၃

Digit at this position in famous constants

π — Pi (π)
Digit 21,023 = 1
e — Euler's number (e)
Digit 21,023 = 1
φ — Golden ratio (φ)
Digit 21,023 = 6
√2 — Pythagoras's (√2)
Digit 21,023 = 3
ln 2 — Natural log of 2
Digit 21,023 = 2
γ — Euler-Mascheroni (γ)
Digit 21,023 = 7

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,019 (gap of 4)
  • Next prime: 21,031 (gap of 8)

Pair status: cousin with 21019.

Unicode codepoint
CJK Unified Ideograph-521F
U+521F
Other letter (Lo)

UTF-8 encoding: E5 88 9F (3 bytes).

Hex color
#00521F
RGB(0, 82, 31)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.31.

Address
0.0.82.31
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.31

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

Position in π

The digit sequence 21023 first appears in π at position 123,006 of the decimal expansion (the 123,006ordinal-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.