1,091
1,091 is a prime, odd, a calendar year.
Historical context — 1091 AD
Calendar year
Year 1091 (MXCI) was a common year starting on Wednesday of the Julian calendar.
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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
-
53
Long year: contains 53 ISO weeks.
- Started on
-
Thursday
January 1, 1091
- Ended on
-
Thursday
December 31, 1091
- Friday the 13ths
-
3
3 Friday the 13ths this year.
- Decade
-
1090s
1090–1099
- Century
-
11th century
1001–1100
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
935
935 years before 2026.
In other calendars
- Hebrew
-
4851 / 4852 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
483 / 484 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Goat
Sexagenary cycle position 8 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1634 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
469 / 470 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1083 / 1084 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1013 / 1012 Saka
Indian national calendar; year starts in March.
Properties
Primality
1,091 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand ninety-one
- Ordinal
- 1091st
- Roman numeral
- MXCI
- Binary
- 10001000011
- Octal
- 2103
- Hexadecimal
- 0x443
- Base64
- BEM=
- One's complement
- 64,444 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵αϟαʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋫
- Chinese
- 一千零九十一
- Chinese (financial)
- 壹仟零玖拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,091 = 2
- e — Euler's number (e)
- Digit 1,091 = 3
- φ — Golden ratio (φ)
- Digit 1,091 = 4
- √2 — Pythagoras's (√2)
- Digit 1,091 = 2
- ln 2 — Natural log of 2
- Digit 1,091 = 3
- γ — Euler-Mascheroni (γ)
- Digit 1,091 = 0
Also seen as
UTF-8 encoding: D1 83 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.67.
- Address
- 0.0.4.67
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.4.67
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1091 first appears in π at position 6,123 of the decimal expansion (the 6,123ordinal-suffix:rd 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.