1,081
1,081 is a composite number, odd, a calendar year.
Historical context — 1081 AD
Calendar year
Year 1081 (MLXXXI) was a common year starting on Friday 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
- 52
- Started on
-
Saturday
January 1, 1081
- Ended on
-
Saturday
December 31, 1081
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
1080s
1080–1089
- Century
-
11th century
1001–1100
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
945
945 years before 2026.
In other calendars
- Hebrew
-
4841 / 4842 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
473 / 474 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Rooster
Sexagenary cycle position 58 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
1624 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
459 / 460 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1073 / 1074 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1003 / 1002 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 10
- Digit product
- 0
- Digital root
- 1
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 1,801
- Flips to (rotate 180°)
- 1,801
- Recamán's sequence
- a(4,257) = 1,081
- Square (n²)
- 1,168,561
- Cube (n³)
- 1,263,214,441
- Divisor count
- 4
- σ(n) — sum of divisors
- 1,152
- φ(n) — Euler's totient
- 1,012
- Sum of prime factors
- 70
Primality
Prime factorization: 23 × 47
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand eighty-one
- Ordinal
- 1081st
- Roman numeral
- MLXXXI
- Binary
- 10000111001
- Octal
- 2071
- Hexadecimal
- 0x439
- Base64
- BDk=
- One's complement
- 64,454 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹
- Egyptian hieroglyphic
- 𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵απαʹ
- Mayan (base 20)
- 𝋢·𝋮·𝋡
- Chinese
- 一千零八十一
- Chinese (financial)
- 壹仟零捌拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,081 = 1
- e — Euler's number (e)
- Digit 1,081 = 3
- φ — Golden ratio (φ)
- Digit 1,081 = 4
- √2 — Pythagoras's (√2)
- Digit 1,081 = 8
- ln 2 — Natural log of 2
- Digit 1,081 = 0
- γ — Euler-Mascheroni (γ)
- Digit 1,081 = 2
Also seen as
UTF-8 encoding: D0 B9 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.57.
- Address
- 0.0.4.57
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.4.57
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1081 first appears in π at position 9,532 of the decimal expansion (the 9,532ordinal-suffix:nd 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.