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21,087

21,087 is a composite number, odd.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).
Arithmetic Number Deficient Number Gapful Number Odious Number Recamán's Sequence

Properties

Parity
Odd
Digit count
5
Digit sum
18
Digit product
0
Digital root
9
Palindrome
No
Bit width
15 bits
Reversed
78,012
Recamán's sequence
a(41,665) = 21,087
Square (n²)
444,661,569
Cube (n³)
9,376,578,505,503
Divisor count
16
σ(n) — sum of divisors
34,560
φ(n) — Euler's totient
12,600
Sum of prime factors
91

Primality

Prime factorization: 3 3 × 11 × 71

Nearest primes: 21,067 (−20) · 21,089 (+2)

Divisors & multiples

All divisors (16)
1 · 3 · 9 · 11 · 27 · 33 · 71 · 99 · 213 · 297 · 639 · 781 · 1917 · 2343 · 7029 · 21087
Aliquot sum (sum of proper divisors): 13,473
Factor pairs (a × b = 21,087)
1 × 21087
3 × 7029
9 × 2343
11 × 1917
27 × 781
33 × 639
71 × 297
99 × 213
First multiples
21,087 · 42,174 (double) · 63,261 · 84,348 · 105,435 · 126,522 · 147,609 · 168,696 · 189,783 · 210,870

Sums & aliquot sequence

As consecutive integers: 10,543 + 10,544 7,028 + 7,029 + 7,030 3,512 + 3,513 + 3,514 + 3,515 + 3,516 + 3,517 2,339 + 2,340 + … + 2,347
Aliquot sequence: 21,087 13,473 6,527 169 14 10 8 7 1 0 — terminates at zero

Representations

In words
twenty-one thousand eighty-seven
Ordinal
21087th
Binary
101001001011111
Octal
51137
Hexadecimal
0x525F
Base64
Ul8=
One's complement
44,448 (16-bit)
In other bases
ternary (3) 1001221000
quaternary (4) 11021133
quinary (5) 1133322
senary (6) 241343
septenary (7) 115323
nonary (9) 31830
undecimal (11) 14930
duodecimal (12) 10253
tridecimal (13) 97a1
tetradecimal (14) 7983
pentadecimal (15) 63ac

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵καπζʹ
Mayan (base 20)
𝋢·𝋬·𝋮·𝋧
Chinese
二萬一千零八十七
Chinese (financial)
貳萬壹仟零捌拾柒
In other modern scripts
Eastern Arabic ٢١٠٨٧ Devanagari २१०८७ Bengali ২১০৮৭ Tamil ௨௧௦௮௭ Thai ๒๑๐๘๗ Tibetan ༢༡༠༨༧ Khmer ២១០៨៧ Lao ໒໑໐໘໗ Burmese ၂၁၀၈၇

Digit at this position in famous constants

π — Pi (π)
Digit 21,087 = 4
e — Euler's number (e)
Digit 21,087 = 8
φ — Golden ratio (φ)
Digit 21,087 = 8
√2 — Pythagoras's (√2)
Digit 21,087 = 0
ln 2 — Natural log of 2
Digit 21,087 = 9
γ — Euler-Mascheroni (γ)
Digit 21,087 = 4

Also seen as

Unicode codepoint
CJK Unified Ideograph-525F
U+525F
Other letter (Lo)

UTF-8 encoding: E5 89 9F (3 bytes).

Hex color
#00525F
RGB(0, 82, 95)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.95.

Address
0.0.82.95
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.95

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

Position in π

The digit sequence 21087 first appears in π at position 10,280 of the decimal expansion (the 10,280ordinal-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.