1,820
1,820 is a composite number, even, a calendar year.
Notable events — 1820 AD
- Mar 6 Congress passes the Missouri Compromise admitting Missouri as a slave state.
- Jan 29 George III dies after a 59-year reign; George IV succeeds him.
- Jul 2 The Revolution of 1820 begins in Naples.
- Mar 15 Maine becomes the 23rd US state.
- Aug 11 The first arrivals of British settlers reach the Cape Colony in the "1820 settlers" scheme.
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
Year facts
- Year type
-
Leap year
Divisible by 4 and not by 100; February has 29 days.
- Days in year
- 366
- ISO weeks
- 52
- Started on
-
Saturday
January 1, 1820
- Ended on
-
Sunday
December 31, 1820
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 2
Sunday, April 2, 1820
- Decade
-
1820s
1820–1829
- Century
-
19th century
1801–1900
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
206
206 years before 2026.
- US presidential election
-
Yes
US holds a presidential election in years divisible by 4 starting from 1788.
In other calendars
- Hebrew
-
5580 / 5581 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1235 / 1236 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
-
2363 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1198 / 1199 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1812 / 1813 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1742 / 1741 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 2 × 5 × 7 × 13
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand eight hundred twenty
- Ordinal
- 1820th
- Roman numeral
- MDCCCXX
- Binary
- 11100011100
- Octal
- 3434
- Hexadecimal
- 0x71C
- Base64
- Bxw=
- One's complement
- 63,715 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋 𒌋𒌋
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆
- Greek (Milesian)
- ͵αωκʹ
- Mayan (base 20)
- 𝋤·𝋫·𝋠
- Chinese
- 一千八百二十
- Chinese (financial)
- 壹仟捌佰貳拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,820 = 9
- e — Euler's number (e)
- Digit 1,820 = 7
- φ — Golden ratio (φ)
- Digit 1,820 = 4
- √2 — Pythagoras's (√2)
- Digit 1,820 = 2
- ln 2 — Natural log of 2
- Digit 1,820 = 9
- γ — Euler-Mascheroni (γ)
- Digit 1,820 = 5
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1820, here are decompositions:
- 19 + 1801 = 1820
- 31 + 1789 = 1820
- 37 + 1783 = 1820
- 43 + 1777 = 1820
- 61 + 1759 = 1820
- 67 + 1753 = 1820
- 73 + 1747 = 1820
- 79 + 1741 = 1820
Showing the first eight; more decompositions exist.
UTF-8 encoding: DC 9C (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.28.
- Address
- 0.0.7.28
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.28
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1820 first appears in π at position 24,653 of the decimal expansion (the 24,653ordinal-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.