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21,398

21,398 is a composite number, even.

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 Evil Number Recamán's Sequence Sphenic Number Squarefree

Properties

Parity
Even
Digit count
5
Digit sum
23
Digit product
432
Digital root
5
Palindrome
No
Bit width
15 bits
Reversed
89,312
Recamán's sequence
a(41,043) = 21,398
Square (n²)
457,874,404
Cube (n³)
9,797,596,496,792
Divisor count
8
σ(n) — sum of divisors
34,608
φ(n) — Euler's totient
9,864
Sum of prime factors
838

Primality

Prime factorization: 2 × 13 × 823

Nearest primes: 21,397 (−1) · 21,401 (+3)

Divisors & multiples

All divisors (8)
1 · 2 · 13 · 26 · 823 · 1646 · 10699 (half) · 21398
Aliquot sum (sum of proper divisors): 13,210
Factor pairs (a × b = 21,398)
1 × 21398
2 × 10699
13 × 1646
26 × 823
First multiples
21,398 · 42,796 (double) · 64,194 · 85,592 · 106,990 · 128,388 · 149,786 · 171,184 · 192,582 · 213,980

Sums & aliquot sequence

As consecutive integers: 5,348 + 5,349 + 5,350 + 5,351 1,640 + 1,641 + … + 1,652 386 + 387 + … + 437
Aliquot sequence: 21,398 13,210 10,586 5,734 3,194 1,600 2,337 1,023 513 287 49 8 7 1 0 — terminates at zero

Representations

In words
twenty-one thousand three hundred ninety-eight
Ordinal
21398th
Binary
101001110010110
Octal
51626
Hexadecimal
0x5396
Base64
U5Y=
One's complement
44,137 (16-bit)
In other bases
ternary (3) 1002100112
quaternary (4) 11032112
quinary (5) 1141043
senary (6) 243022
septenary (7) 116246
nonary (9) 32315
undecimal (11) 15093
duodecimal (12) 10472
tridecimal (13) 9980
tetradecimal (14) 7b26
pentadecimal (15) 6518

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵κατϟηʹ
Mayan (base 20)
𝋢·𝋭·𝋩·𝋲
Chinese
二萬一千三百九十八
Chinese (financial)
貳萬壹仟參佰玖拾捌
In other modern scripts
Eastern Arabic ٢١٣٩٨ Devanagari २१३९८ Bengali ২১৩৯৮ Tamil ௨௧௩௯௮ Thai ๒๑๓๙๘ Tibetan ༢༡༣༩༨ Khmer ២១៣៩៨ Lao ໒໑໓໙໘ Burmese ၂၁၃၉၈

Digit at this position in famous constants

π — Pi (π)
Digit 21,398 = 1
e — Euler's number (e)
Digit 21,398 = 2
φ — Golden ratio (φ)
Digit 21,398 = 3
√2 — Pythagoras's (√2)
Digit 21,398 = 1
ln 2 — Natural log of 2
Digit 21,398 = 9
γ — Euler-Mascheroni (γ)
Digit 21,398 = 4

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21398, here are decompositions:

  • 7 + 21391 = 21398
  • 19 + 21379 = 21398
  • 79 + 21319 = 21398
  • 151 + 21247 = 21398
  • 211 + 21187 = 21398
  • 229 + 21169 = 21398
  • 241 + 21157 = 21398
  • 277 + 21121 = 21398

Showing the first eight; more decompositions exist.

Unicode codepoint
CJK Unified Ideograph-5396
U+5396
Other letter (Lo)

UTF-8 encoding: E5 8E 96 (3 bytes).

Hex color
#005396
RGB(0, 83, 150)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.150.

Address
0.0.83.150
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.83.150

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

Position in π

The digit sequence 21398 first appears in π at position 112,721 of the decimal expansion (the 112,721ordinal-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.