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Number

800

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

Abundant Number Achilles Number Flippable Gapful Number Harshad / Niven Odious Number Pernicious Number Powerful Number Practical Number Recamán's Sequence Semiperfect Number Year

Notable events — 800 AD

  1. Dec 25 Pope Leo III crowns Charlemagne Emperor of the Romans in St. Peter's Basilica.

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

Historical context — 800 BC

Decade

This article concerns the period 809 BC – 800 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 400 (Gregorian leap-year rule exception to the century rule).
Days in year
366
ISO weeks
52
Started on
Saturday
January 1, 800
Ended on
Sunday
December 31, 800
Friday the 13ths
1
One Friday the 13th this year.
Decade
800s
800–809
Century
8th century
701–800
Millennium
1st millennium
1–1000
Years ago
1,226
1226 years before 2026.

In other calendars

Hebrew
4560 / 4561 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
183 / 184 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Metal zodiac:Dragon
Sexagenary cycle position 17 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1343 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
178 / 179 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
792 / 793 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
722 / 721 Saka
Indian national calendar; year starts in March.

Properties

Parity
Even
Digit count
3
Digit sum
8
Digit product
0
Digital root
8
Palindrome
No
Bit width
10 bits
Reversed
8
Flips to (rotate 180°)
8
Recamán's sequence
a(291) = 800
Square (n²)
640,000
Cube (n³)
512,000,000
Divisor count
18
σ(n) — sum of divisors
1,953
φ(n) — Euler's totient
320
Sum of prime factors
20

Primality

Prime factorization: 2 5 × 5 2

Nearest primes: 797 (−3) · 809 (+9)

Divisors & multiples

All divisors (18)
1 · 2 · 4 · 5 · 8 · 10 · 16 · 20 · 25 · 32 · 40 · 50 · 80 · 100 · 160 · 200 · 400 (half) · 800
Aliquot sum (sum of proper divisors): 1,153
Factor pairs (a × b = 800)
1 × 800
2 × 400
4 × 200
5 × 160
8 × 100
10 × 80
16 × 50
20 × 40
25 × 32
First multiples
800 · 1,600 (double) · 2,400 · 3,200 · 4,000 · 4,800 · 5,600 · 6,400 · 7,200 · 8,000

Sums & aliquot sequence

As a sum of two squares: 4² + 28² = 20² + 20²
As consecutive integers: 158 + 159 + 160 + 161 + 162 20 + 21 + … + 44
Aliquot sequence: 800 1,153 1 0 — terminates at zero

Representations

In words
eight hundred
Ordinal
800th
Roman numeral
DCCC
Binary
1100100000
Octal
1440
Hexadecimal
0x320
Base64
AyA=
One's complement
64,735 (16-bit)
In other bases
ternary (3) 1002122
quaternary (4) 30200
quinary (5) 11200
senary (6) 3412
septenary (7) 2222
nonary (9) 1078
undecimal (11) 668
duodecimal (12) 568
tridecimal (13) 497
tetradecimal (14) 412
pentadecimal (15) 385

Historical numeral systems

Babylonian (base 60)
𒌋𒁹𒁹𒁹 𒌋𒌋
Egyptian hieroglyphic
𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢
Greek (Milesian)
ωʹ
Mayan (base 20)
𝋢·𝋠·𝋠
Chinese
八百
Chinese (financial)
捌佰
In other modern scripts
Eastern Arabic ٨٠٠ Devanagari ८०० Bengali ৮০০ Tamil ௮௦௦ Thai ๘๐๐ Tibetan ༨༠༠ Khmer ៨០០ Lao ໘໐໐ Burmese ၈၀၀

Digit at this position in famous constants

π — Pi (π)
Digit 800 = 5
e — Euler's number (e)
Digit 800 = 9
φ — Golden ratio (φ)
Digit 800 = 7
√2 — Pythagoras's (√2)
Digit 800 = 9
ln 2 — Natural log of 2
Digit 800 = 4
γ — Euler-Mascheroni (γ)
Digit 800 = 8

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 800, here are decompositions:

  • 3 + 797 = 800
  • 13 + 787 = 800
  • 31 + 769 = 800
  • 43 + 757 = 800
  • 61 + 739 = 800
  • 67 + 733 = 800
  • 73 + 727 = 800
  • 109 + 691 = 800

Showing the first eight; more decompositions exist.

Unicode codepoint
̠
Combining Minus Sign Below
U+0320
Non-spacing mark (Mn)

UTF-8 encoding: CC A0 (2 bytes).

Hex color
#000320
RGB(0, 3, 32)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.32.

Address
0.0.3.32
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.3.32

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

NANP area code 800

The number 800 is an active NANP area code (North American Numbering Plan).

Primary area
Toll-free
Region
(special)
Country
North America

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