number.wiki
Number

812

812 is a composite number, even, a calendar year.

Abundant Number Arithmetic Number Odious Number Pernicious Number Practical Number Pronic / Oblong Recamán's Sequence Semiperfect Number Year

Historical context — 812 AD

Calendar year

Year 812 (DCCCXII) was a leap year starting on Thursday of the Julian calendar, the 812th year of the Common Era (CE) and Anno Domini (AD) designations, the 812th year of the 1st millennium, the 12th year of the 9th century, and the 3rd year of the 810s decade.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Historical context — 812 BC

Decade

This article concerns the period 819 BC – 810 BC.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Year facts

Year type
Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year
366
ISO weeks
52
Started on
Sunday
January 1, 812
Ended on
Monday
December 31, 812
Friday the 13ths
3
3 Friday the 13ths this year.
Decade
810s
810–819
Century
9th century
801–900
Millennium
1st millennium
1–1000
Years ago
1,214
1214 years before 2026.

In other calendars

Hebrew
4572 / 4573 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
196 / 197 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Water zodiac:Dragon
Sexagenary cycle position 29 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1355 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
190 / 191 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
804 / 805 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
734 / 733 Saka
Indian national calendar; year starts in March.

Properties

Parity
Even
Digit count
3
Digit sum
11
Digit product
16
Digital root
2
Palindrome
No
Bit width
10 bits
Reversed
218
Recamán's sequence
a(2,124) = 812
Square (n²)
659,344
Cube (n³)
535,387,328
Divisor count
12
σ(n) — sum of divisors
1,680
φ(n) — Euler's totient
336
Sum of prime factors
40

Primality

Prime factorization: 2 2 × 7 × 29

Nearest primes: 811 (−1) · 821 (+9)

Divisors & multiples

All divisors (12)
1 · 2 · 4 · 7 · 14 · 28 · 29 · 58 · 116 · 203 · 406 (half) · 812
Aliquot sum (sum of proper divisors): 868
Factor pairs (a × b = 812)
1 × 812
2 × 406
4 × 203
7 × 116
14 × 58
28 × 29
First multiples
812 · 1,624 (double) · 2,436 · 3,248 · 4,060 · 4,872 · 5,684 · 6,496 · 7,308 · 8,120

Sums & aliquot sequence

As consecutive integers: 113 + 114 + … + 119 98 + 99 + … + 105 14 + 15 + … + 42
Aliquot sequence: 812 868 924 1,764 3,423 1,825 469 75 49 8 7 1 0 — terminates at zero

Representations

In words
eight hundred twelve
Ordinal
812th
Roman numeral
DCCCXII
Binary
1100101100
Octal
1454
Hexadecimal
0x32C
Base64
Ayw=
One's complement
64,723 (16-bit)
In other bases
ternary (3) 1010002
quaternary (4) 30230
quinary (5) 11222
senary (6) 3432
septenary (7) 2240
nonary (9) 1102
undecimal (11) 679
duodecimal (12) 578
tridecimal (13) 4a6
tetradecimal (14) 420
pentadecimal (15) 392

Historical numeral systems

Babylonian (base 60)
𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹
Egyptian hieroglyphic
𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺
Greek (Milesian)
ωιβʹ
Mayan (base 20)
𝋢·𝋠·𝋬
Chinese
八百一十二
Chinese (financial)
捌佰壹拾貳
In other modern scripts
Eastern Arabic ٨١٢ Devanagari ८१२ Bengali ৮১২ Tamil ௮௧௨ Thai ๘๑๒ Tibetan ༨༡༢ Khmer ៨១២ Lao ໘໑໒ Burmese ၈၁၂

Digit at this position in famous constants

π — Pi (π)
Digit 812 = 3
e — Euler's number (e)
Digit 812 = 6
φ — Golden ratio (φ)
Digit 812 = 7
√2 — Pythagoras's (√2)
Digit 812 = 5
ln 2 — Natural log of 2
Digit 812 = 1
γ — Euler-Mascheroni (γ)
Digit 812 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 812, here are decompositions:

  • 3 + 809 = 812
  • 43 + 769 = 812
  • 61 + 751 = 812
  • 73 + 739 = 812
  • 79 + 733 = 812
  • 103 + 709 = 812
  • 139 + 673 = 812
  • 151 + 661 = 812

Showing the first eight; more decompositions exist.

Unicode codepoint
̬
Combining Caron Below
U+032C
Non-spacing mark (Mn)

UTF-8 encoding: CC AC (2 bytes).

Hex color
#00032C
RGB(0, 3, 44)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.44.

Address
0.0.3.44
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.3.44

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

NANP area code 812

The number 812 is an active NANP area code (North American Numbering Plan).

Primary area
Evansville / Bloomington
Region
Indiana
Country
United States

Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.