Number

2,091

2,091 is a composite number, odd, a calendar year.

2,091 (two thousand ninety-one) is an odd 4-digit number. It is a composite number with 8 divisors, and factors as 3 × 17 × 41. Written other ways, in Roman numerals it is MMXCI and in binary, 100000101011.

Arithmetic Number Cube-Free Deficient Number Happy Number Odious Number Pernicious Number Recamán's Sequence Sphenic Number Squarefree Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

2,079 2,080 2,081 2,082 2,083 2,084 2,085 2,086 2,087 2,088 2,089 2,090 2,091 2,092 2,093 2,094 2,095 2,096 2,097 2,098 2,099 2,100 2,101 2,102 2,103

less more

Historical context — 2091 AD

Current millennium spanning the years 2001 to 3000

The third millennium of the Anno Domini or Common Era is the current millennium spanning the years 2001 to 3000.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 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: Monday
January 1, 2091
Ended on: Monday
December 31, 2091
Friday the 13ths: 2
2 Friday the 13ths this year.
Easter Sunday: April 8
Sunday, April 8, 2091
Decade: 2090s
2090–2099
Century: 21st century
2001–2100
Millennium: 3rd millennium
2001–3000
Years until: 65
65 years after 2026.

In other calendars

Hebrew: 5851 / 5852 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1514 / 1515 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Pig
Sexagenary cycle position 48 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2634 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1469 / 1470 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 2083 / 2084 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 2013 / 2012 Saka
Indian national calendar; year starts in March.
Japanese: Reiwa 73
Reign-era counting from the start of each emperor's reign.

Properties

Parity: Odd
Digit count: 4
Digit sum: 12
Digit product: 0
Digital root: 3
Palindrome: No
Bit width: 12 bits
Reversed: 1,902
Recamán's sequence: a(3,569) = 2,091
Square (n²): 4,372,281
Cube (n³): 9,142,439,571
Divisor count: 8
σ(n) — sum of divisors: 3,024
φ(n) — Euler's totient: 1,280
Sum of prime factors: 61

Primality

Prime factorization: 3 × 17 × 41

Nearest primes: 2,089 (−2) · 2,099 (+8)

Divisors & multiples

All divisors (8)

1 · 3 · 17 · 41 · 51 · 123 · 697 · 2091

Aliquot sum (sum of proper divisors): 933

Factor pairs (a × b = 2,091)

1 × 2091

3 × 697

17 × 123

41 × 51

First multiples

2,091 · 4,182 (double) · 6,273 · 8,364 · 10,455 · 12,546 · 14,637 · 16,728 · 18,819 · 20,910

Sums & aliquot sequence

As consecutive integers: 1,045 + 1,046 696 + 697 + 698 346 + 347 + 348 + 349 + 350 + 351 115 + 116 + … + 131

Aliquot sequence: 2,091 → 933 → 315 → 309 → 107 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,091 = [45; (1, 2, 1, 2, 45, 2, 1, 2, 1, 90)]

Period length 10 — the block in parentheses repeats forever.

Representations

In words: two thousand ninety-one
Ordinal: 2091st
Roman numeral: MMXCI
Binary: 100000101011
Octal: 4053
Hexadecimal: 0x82B
Base64: CCs=
One's complement: 63,444 (16-bit)
Scientific notation: 2.091 × 10³
As a duration: 2,091 s = 34 minutes, 51 seconds

In other bases

ternary (3) 2212110

quaternary (4) 200223

quinary (5) 31331

senary (6) 13403

septenary (7) 6045

nonary (9) 2773

undecimal (11) 1631

duodecimal (12) 1263

tridecimal (13) c4b

tetradecimal (14) a95

pentadecimal (15) 946

As an angle

2,091° = 5 × 360° + 291°

291° ≈ 5.079 rad

Compass bearing: WNW (west-northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵βϟαʹ
Mayan (base 20): 𝋥·𝋤·𝋫
Chinese: 二千零九十一
Chinese (financial): 貳仟零玖拾壹

In other modern scripts

Eastern Arabic ٢٠٩١ Devanagari २०९१ Bengali ২০৯১ Tamil ௨௦௯௧ Thai ๒๐๙๑ Tibetan ༢༠༩༡ Khmer ២០៩១ Lao ໒໐໙໑ Burmese ၂၀၉၁

Digit at this position in famous constants

π — Pi (π): Digit 2,091 = 5
e — Euler's number (e): Digit 2,091 = 9
φ — Golden ratio (φ): Digit 2,091 = 5
√2 — Pythagoras's (√2): Digit 2,091 = 1
ln 2 — Natural log of 2: Digit 2,091 = 6
γ — Euler-Mascheroni (γ): Digit 2,091 = 1

Also seen as

Unicode codepoint

ࠫ

Samaritan Vowel Sign O

U+082B

Non-spacing mark (Mn)

UTF-8 encoding: E0 A0 AB (3 bytes).

Lookup U+082B on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00082B

RGB(0, 8, 43)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.43.

Address: 0.0.8.43
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.8.43

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

Musical pitch

Heard as a frequency, 2,091 Hz is closest to:

Concert pitch (A4 = 440 Hz): C7 (2093 Hz, -2¢)
Scientific pitch (C4 = 256 Hz): C7 (2048 Hz, +36¢)
Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, exact)

Position in π

The digit sequence 2091 first appears in π at position 3,390 of the decimal expansion (the 3,390ordinal-suffix:th 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.

Look up 2091 on Pi Search ↗