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Number

1,986

1,986 is a composite number, even, a calendar year.

Abundant Number Arithmetic Number Evil Number Flippable Recamán's Sequence Semiperfect Number Sphenic Number Squarefree Year

Notable events — 1986 AD

  1. Jan 28 The Space Shuttle Challenger explodes 73 seconds after launch; all seven aboard die.
  2. Feb 19 The Soviet Union launches the Mir space station.
  3. Feb 25 The People Power Revolution ousts Philippine President Ferdinand Marcos.
  4. Feb 28 Swedish Prime Minister Olof Palme is assassinated on a Stockholm street.
  5. Apr 26 Reactor 4 at the Chernobyl nuclear plant explodes, contaminating much of Europe.
  6. Nov 25 The Iran-Contra affair is publicly revealed in the US.

Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0

Year facts

Year type
Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year
365
ISO weeks
52
Started on
Wednesday
January 1, 1986
Ended on
Wednesday
December 31, 1986
Friday the 13ths
1
One Friday the 13th this year.
Easter Sunday
March 30
Sunday, March 30, 1986
Decade
1980s
1980–1989
Century
20th century
1901–2000
Millennium
2nd millennium
1001–2000
Years ago
40
40 years before 2026.
FIFA World Cup
Yes
Men's FIFA World Cup is held every four years (skipped 1942 and 1946 due to WWII).

In other calendars

Hebrew
5746 / 5747 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
1406 / 1407 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Fire zodiac:Tiger
Sexagenary cycle position 3 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
2529 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
1364 / 1365 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1978 / 1979 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1908 / 1907 Saka
Indian national calendar; year starts in March.
Japanese
Shōwa 61
Reign-era counting from the start of each emperor's reign.

Properties

Parity
Even
Digit count
4
Digit sum
24
Digit product
432
Digital root
6
Palindrome
No
Bit width
11 bits
Reversed
6,891
Flips to (rotate 180°)
9,861
Recamán's sequence
a(3,779) = 1,986
Square (n²)
3,944,196
Cube (n³)
7,833,173,256
Divisor count
8
σ(n) — sum of divisors
3,984
φ(n) — Euler's totient
660
Sum of prime factors
336

Primality

Prime factorization: 2 × 3 × 331

Nearest primes: 1,979 (−7) · 1,987 (+1)

Divisors & multiples

All divisors (8)
1 · 2 · 3 · 6 · 331 · 662 · 993 (half) · 1986
Aliquot sum (sum of proper divisors): 1,998
Factor pairs (a × b = 1,986)
1 × 1986
2 × 993
3 × 662
6 × 331
First multiples
1,986 · 3,972 (double) · 5,958 · 7,944 · 9,930 · 11,916 · 13,902 · 15,888 · 17,874 · 19,860

Sums & aliquot sequence

As consecutive integers: 661 + 662 + 663 495 + 496 + 497 + 498 160 + 161 + … + 171
Aliquot sequence: 1,986 1,998 2,562 3,390 4,818 5,838 7,602 9,870 17,778 17,790 24,978 27,438 30,882 30,894 34,386 40,782 52,530 — unresolved within range

Representations

In words
one thousand nine hundred eighty-six
Ordinal
1986th
Roman numeral
MCMLXXXVI
Binary
11111000010
Octal
3702
Hexadecimal
0x7C2
Base64
B8I=
One's complement
63,549 (16-bit)
In other bases
ternary (3) 2201120
quaternary (4) 133002
quinary (5) 30421
senary (6) 13110
septenary (7) 5535
nonary (9) 2646
undecimal (11) 1546
duodecimal (12) 1196
tridecimal (13) b9a
tetradecimal (14) a1c
pentadecimal (15) 8c6

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒌋𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵αϡπϛʹ
Mayan (base 20)
𝋤·𝋳·𝋦
Chinese
一千九百八十六
Chinese (financial)
壹仟玖佰捌拾陸
In other modern scripts
Eastern Arabic ١٩٨٦ Devanagari १९८६ Bengali ১৯৮৬ Tamil ௧௯௮௬ Thai ๑๙๘๖ Tibetan ༡༩༨༦ Khmer ១៩៨៦ Lao ໑໙໘໖ Burmese ၁၉၈၆

Digit at this position in famous constants

π — Pi (π)
Digit 1,986 = 1
e — Euler's number (e)
Digit 1,986 = 7
φ — Golden ratio (φ)
Digit 1,986 = 0
√2 — Pythagoras's (√2)
Digit 1,986 = 7
ln 2 — Natural log of 2
Digit 1,986 = 6
γ — Euler-Mascheroni (γ)
Digit 1,986 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1986, here are decompositions:

  • 7 + 1979 = 1986
  • 13 + 1973 = 1986
  • 37 + 1949 = 1986
  • 53 + 1933 = 1986
  • 73 + 1913 = 1986
  • 79 + 1907 = 1986
  • 97 + 1889 = 1986
  • 107 + 1879 = 1986

Showing the first eight; more decompositions exist.

Unicode codepoint
߂
Nko Digit Two
U+07C2
Decimal digit (Nd)

UTF-8 encoding: DF 82 (2 bytes).

Hex color
#0007C2
RGB(0, 7, 194)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.194.

Address
0.0.7.194
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.7.194

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

Possible US bank routing number

This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.

Routing number
000001986
Federal Reserve
United States Government

Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.

Position in π

The digit sequence 1986 first appears in π at position 4,531 of the decimal expansion (the 4,531ordinal-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.