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Number

805

805 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Odious Number Pernicious Number Recamán's Sequence Sphenic Number Squarefree Year

Historical context — 805 AD

Calendar year

Year 805 (DCCCV) was a common year starting on Wednesday of the Julian calendar, the 805th year of the Common Era (CE) and Anno Domini (AD) designations, the 805th year of the 1st millennium, the 5th year of the 9th century, and the 6th year of the 800s decade.

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Historical context — 805 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
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
Saturday
January 1, 805
Ended on
Saturday
December 31, 805
Friday the 13ths
1
One Friday the 13th this year.
Decade
800s
800–809
Century
9th century
801–900
Millennium
1st millennium
1–1000
Years ago
1,221
1221 years before 2026.

In other calendars

Hebrew
4565 / 4566 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
189 / 190 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Wood zodiac:Rooster
Sexagenary cycle position 22 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1348 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
183 / 184 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
797 / 798 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
727 / 726 Saka
Indian national calendar; year starts in March.

Properties

Parity
Odd
Digit count
3
Digit sum
13
Digit product
0
Digital root
4
Palindrome
No
Bit width
10 bits
Reversed
508
Recamán's sequence
a(2,138) = 805
Square (n²)
648,025
Cube (n³)
521,660,125
Divisor count
8
σ(n) — sum of divisors
1,152
φ(n) — Euler's totient
528
Sum of prime factors
35

Primality

Prime factorization: 5 × 7 × 23

Nearest primes: 797 (−8) · 809 (+4)

Divisors & multiples

All divisors (8)
1 · 5 · 7 · 23 · 35 · 115 · 161 · 805
Aliquot sum (sum of proper divisors): 347
Factor pairs (a × b = 805)
1 × 805
5 × 161
7 × 115
23 × 35
First multiples
805 · 1,610 (double) · 2,415 · 3,220 · 4,025 · 4,830 · 5,635 · 6,440 · 7,245 · 8,050

Sums & aliquot sequence

As consecutive integers: 402 + 403 159 + 160 + 161 + 162 + 163 112 + 113 + … + 118 76 + 77 + … + 85
Aliquot sequence: 805 347 1 0 — terminates at zero

Representations

In words
eight hundred five
Ordinal
805th
Roman numeral
DCCCV
Binary
1100100101
Octal
1445
Hexadecimal
0x325
Base64
AyU=
One's complement
64,730 (16-bit)
In other bases
ternary (3) 1002211
quaternary (4) 30211
quinary (5) 11210
senary (6) 3421
septenary (7) 2230
nonary (9) 1084
undecimal (11) 672
duodecimal (12) 571
tridecimal (13) 49c
tetradecimal (14) 417
pentadecimal (15) 38a

Historical numeral systems

Babylonian (base 60)
𒌋𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
ωεʹ
Mayan (base 20)
𝋢·𝋠·𝋥
Chinese
八百零五
Chinese (financial)
捌佰零伍
In other modern scripts
Eastern Arabic ٨٠٥ Devanagari ८०५ Bengali ৮০৫ Tamil ௮௦௫ Thai ๘๐๕ Tibetan ༨༠༥ Khmer ៨០៥ Lao ໘໐໕ Burmese ၈၀၅

Digit at this position in famous constants

π — Pi (π)
Digit 805 = 4
e — Euler's number (e)
Digit 805 = 7
φ — Golden ratio (φ)
Digit 805 = 7
√2 — Pythagoras's (√2)
Digit 805 = 6
ln 2 — Natural log of 2
Digit 805 = 9
γ — Euler-Mascheroni (γ)
Digit 805 = 9

Also seen as

Unicode codepoint
̥
Combining Ring Below
U+0325
Non-spacing mark (Mn)

UTF-8 encoding: CC A5 (2 bytes).

Hex color
#000325
RGB(0, 3, 37)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.37.

Address
0.0.3.37
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.3.37

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

NANP area code 805

The number 805 is an active NANP area code (North American Numbering Plan).

Primary area
Santa Barbara / Ventura
Region
California
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.

Calculator-display word

Type 805 on a seven-segment calculator, flip it 180°, and the display reads:

SOB

A staple of calculator humor since pocket calculators put digits in front of bored students.