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Number

21,031

21,031 is a prime, odd.

Arithmetic Number Deficient Number Odious Number Pernicious Number Prime Recamán's Sequence Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
7
Digit product
0
Digital root
7
Palindrome
No
Bit width
15 bits
Reversed
13,012
Recamán's sequence
a(41,777) = 21,031
Square (n²)
442,302,961
Cube (n³)
9,302,073,572,791
Divisor count
2
σ(n) — sum of divisors
21,032
φ(n) — Euler's totient
21,030

Primality

21,031 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21031
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,031)
1 × 21031
First multiples
21,031 · 42,062 (double) · 63,093 · 84,124 · 105,155 · 126,186 · 147,217 · 168,248 · 189,279 · 210,310

Sums & aliquot sequence

As consecutive integers: 10,515 + 10,516

Representations

In words
twenty-one thousand thirty-one
Ordinal
21031st
Binary
101001000100111
Octal
51047
Hexadecimal
0x5227
Base64
Uic=
One's complement
44,504 (16-bit)
In other bases
ternary (3) 1001211221
quaternary (4) 11020213
quinary (5) 1133111
senary (6) 241211
septenary (7) 115213
nonary (9) 31757
undecimal (11) 1488a
duodecimal (12) 10207
tridecimal (13) 975a
tetradecimal (14) 7943
pentadecimal (15) 6371

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓎆𓎆𓎆𓏺
Greek (Milesian)
͵καλαʹ
Mayan (base 20)
𝋢·𝋬·𝋫·𝋫
Chinese
二萬一千零三十一
Chinese (financial)
貳萬壹仟零參拾壹
In other modern scripts
Eastern Arabic ٢١٠٣١ Devanagari २१०३१ Bengali ২১০৩১ Tamil ௨௧௦௩௧ Thai ๒๑๐๓๑ Tibetan ༢༡༠༣༡ Khmer ២១០៣១ Lao ໒໑໐໓໑ Burmese ၂၁၀၃၁

Digit at this position in famous constants

π — Pi (π)
Digit 21,031 = 0
e — Euler's number (e)
Digit 21,031 = 3
φ — Golden ratio (φ)
Digit 21,031 = 7
√2 — Pythagoras's (√2)
Digit 21,031 = 3
ln 2 — Natural log of 2
Digit 21,031 = 0
γ — Euler-Mascheroni (γ)
Digit 21,031 = 8

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,023 (gap of 8)
  • Next prime: 21,059 (gap of 28)
Unicode codepoint
CJK Unified Ideograph-5227
U+5227
Other letter (Lo)

UTF-8 encoding: E5 88 A7 (3 bytes).

Hex color
#005227
RGB(0, 82, 39)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.39.

Address
0.0.82.39
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.39

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

Position in π

The digit sequence 21031 first appears in π at position 14,531 of the decimal expansion (the 14,531ordinal-suffix:st 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.