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Number

21,017

21,017 is a prime, odd.

Arithmetic Number Chen Prime Cousin Prime Deficient Number Evil Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime

Properties

Parity
Odd
Digit count
5
Digit sum
11
Digit product
0
Digital root
2
Palindrome
No
Bit width
15 bits
Reversed
71,012
Recamán's sequence
a(41,805) = 21,017
Square (n²)
441,714,289
Cube (n³)
9,283,509,211,913
Divisor count
2
σ(n) — sum of divisors
21,018
φ(n) — Euler's totient
21,016

Primality

21,017 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21017
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,017)
1 × 21017
First multiples
21,017 · 42,034 (double) · 63,051 · 84,068 · 105,085 · 126,102 · 147,119 · 168,136 · 189,153 · 210,170

Sums & aliquot sequence

As a sum of two squares: 101² + 104²
As consecutive integers: 10,508 + 10,509

Representations

In words
twenty-one thousand seventeen
Ordinal
21017th
Binary
101001000011001
Octal
51031
Hexadecimal
0x5219
Base64
Uhk=
One's complement
44,518 (16-bit)
In other bases
ternary (3) 1001211102
quaternary (4) 11020121
quinary (5) 1133032
senary (6) 241145
septenary (7) 115163
nonary (9) 31742
undecimal (11) 14877
duodecimal (12) 101b5
tridecimal (13) 9749
tetradecimal (14) 7933
pentadecimal (15) 6362

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵καιζʹ
Mayan (base 20)
𝋢·𝋬·𝋪·𝋱
Chinese
二萬一千零一十七
Chinese (financial)
貳萬壹仟零壹拾柒
In other modern scripts
Eastern Arabic ٢١٠١٧ Devanagari २१०१७ Bengali ২১০১৭ Tamil ௨௧௦௧௭ Thai ๒๑๐๑๗ Tibetan ༢༡༠༡༧ Khmer ២១០១៧ Lao ໒໑໐໑໗ Burmese ၂၁၀၁၇

Digit at this position in famous constants

π — Pi (π)
Digit 21,017 = 2
e — Euler's number (e)
Digit 21,017 = 1
φ — Golden ratio (φ)
Digit 21,017 = 1
√2 — Pythagoras's (√2)
Digit 21,017 = 1
ln 2 — Natural log of 2
Digit 21,017 = 6
γ — Euler-Mascheroni (γ)
Digit 21,017 = 7

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,013 (gap of 4)
  • Next prime: 21,019 (gap of 2)

Pair status: twin with 21019, cousin with 21013.

Unicode codepoint
CJK Unified Ideograph-5219
U+5219
Other letter (Lo)

UTF-8 encoding: E5 88 99 (3 bytes).

Hex color
#005219
RGB(0, 82, 25)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.25.

Address
0.0.82.25
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.25

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

Position in π

The digit sequence 21017 first appears in π at position 60,651 of the decimal expansion (the 60,651ordinal-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.