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19,840

19,840 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.).
Abundant Number Arithmetic Number Gapful Number Odious Number Pernicious Number Practical Number Semiperfect Number

Properties

Parity
Even
Digit count
5
Digit sum
22
Digit product
0
Digital root
4
Palindrome
No
Bit width
15 bits
Reversed
4,891
Square (n²)
393,625,600
Cube (n³)
7,809,531,904,000
Divisor count
32
σ(n) — sum of divisors
48,960
φ(n) — Euler's totient
7,680
Sum of prime factors
50

Primality

Prime factorization: 2 7 × 5 × 31

Nearest primes: 19,819 (−21) · 19,841 (+1)

Divisors & multiples

All divisors (32)
1 · 2 · 4 · 5 · 8 · 10 · 16 · 20 · 31 · 32 · 40 · 62 · 64 · 80 · 124 · 128 · 155 · 160 · 248 · 310 · 320 · 496 · 620 · 640 · 992 · 1240 · 1984 · 2480 · 3968 · 4960 · 9920 (half) · 19840
Aliquot sum (sum of proper divisors): 29,120
Factor pairs (a × b = 19,840)
1 × 19840
2 × 9920
4 × 4960
5 × 3968
8 × 2480
10 × 1984
16 × 1240
20 × 992
31 × 640
32 × 620
40 × 496
62 × 320
64 × 310
80 × 248
124 × 160
128 × 155
First multiples
19,840 · 39,680 (double) · 59,520 · 79,360 · 99,200 · 119,040 · 138,880 · 158,720 · 178,560 · 198,400

Sums & aliquot sequence

As consecutive integers: 3,966 + 3,967 + 3,968 + 3,969 + 3,970 625 + 626 + … + 655 51 + 52 + … + 205
Aliquot sequence: 19,840 29,120 56,224 70,784 92,416 102,275 24,577 3,519 2,097 945 975 761 1 0 — terminates at zero

Representations

In words
nineteen thousand eight hundred forty
Ordinal
19840th
Binary
100110110000000
Octal
46600
Hexadecimal
0x4D80
Base64
TYA=
One's complement
45,695 (16-bit)
In other bases
ternary (3) 1000012211
quaternary (4) 10312000
quinary (5) 1113330
senary (6) 231504
septenary (7) 111562
nonary (9) 30184
undecimal (11) 139a7
duodecimal (12) b594
tridecimal (13) 9052
tetradecimal (14) 7332
pentadecimal (15) 5d2a

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋 𒌋𒌋𒌋𒌋
Egyptian hieroglyphic
𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian)
͵ιθωμʹ
Mayan (base 20)
𝋢·𝋩·𝋬·𝋠
Chinese
一萬九千八百四十
Chinese (financial)
壹萬玖仟捌佰肆拾
In other modern scripts
Eastern Arabic ١٩٨٤٠ Devanagari १९८४० Bengali ১৯৮৪০ Tamil ௧௯௮௪௦ Thai ๑๙๘๔๐ Tibetan ༡༩༨༤༠ Khmer ១៩៨៤០ Lao ໑໙໘໔໐ Burmese ၁၉၈၄၀

Digit at this position in famous constants

π — Pi (π)
Digit 19,840 = 3
e — Euler's number (e)
Digit 19,840 = 2
φ — Golden ratio (φ)
Digit 19,840 = 1
√2 — Pythagoras's (√2)
Digit 19,840 = 6
ln 2 — Natural log of 2
Digit 19,840 = 8
γ — Euler-Mascheroni (γ)
Digit 19,840 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 19840, here are decompositions:

  • 47 + 19793 = 19840
  • 89 + 19751 = 19840
  • 101 + 19739 = 19840
  • 113 + 19727 = 19840
  • 131 + 19709 = 19840
  • 179 + 19661 = 19840
  • 257 + 19583 = 19840
  • 263 + 19577 = 19840

Showing the first eight; more decompositions exist.

Unicode codepoint
CJK Unified Ideograph-4D80
U+4D80
Other letter (Lo)

UTF-8 encoding: E4 B6 80 (3 bytes).

Hex color
#004D80
RGB(0, 77, 128)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.77.128.

Address
0.0.77.128
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.77.128

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

Position in π

The digit sequence 19840 first appears in π at position 37,837 of the decimal expansion (the 37,837ordinal-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.