2,021
2,021 is a composite number, odd, a calendar year.
Notable events — 2021 AD
- Jan 6 Supporters of Donald Trump storm the US Capitol during certification of the 2020 election.
- Feb 1 A military coup in Myanmar ousts Aung San Suu Kyi.
- Feb 18 NASA's Perseverance rover lands on Mars at Jezero Crater.
- Feb 19 The United States formally rejoins the Paris Climate Agreement.
- Mar 6 Pope Francis meets Grand Ayatollah Ali al-Sistani in Najaf — the first meeting between a pope and a top Shia cleric.
Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0
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
-
Friday
January 1, 2021
- Ended on
-
Friday
December 31, 2021
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 4
Sunday, April 4, 2021
- Decade
-
2020s
2020–2029
- Century
-
21st century
2001–2100
- Millennium
-
3rd millennium
2001–3000
- Years ago
-
5
5 years before 2026.
In other calendars
- Hebrew
-
5781 / 5782 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1442 / 1443 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Ox
Sexagenary cycle position 38 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2564 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1399 / 1400 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
2013 / 2014 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1943 / 1942 Saka
Indian national calendar; year starts in March.
- Japanese
-
Reiwa 3
Reign-era counting from the start of each emperor's reign.
Properties
Primality
Prime factorization: 43 × 47
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- two thousand twenty-one
- Ordinal
- 2021st
- Roman numeral
- MMXXI
- Binary
- 11111100101
- Octal
- 3745
- Hexadecimal
- 0x7E5
- Base64
- B+U=
- One's complement
- 63,514 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓎆𓎆𓏺
- Greek (Milesian)
- ͵βκαʹ
- Mayan (base 20)
- 𝋥·𝋡·𝋡
- Chinese
- 二千零二十一
- Chinese (financial)
- 貳仟零貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,021 = 3
- e — Euler's number (e)
- Digit 2,021 = 3
- φ — Golden ratio (φ)
- Digit 2,021 = 3
- √2 — Pythagoras's (√2)
- Digit 2,021 = 4
- ln 2 — Natural log of 2
- Digit 2,021 = 7
- γ — Euler-Mascheroni (γ)
- Digit 2,021 = 9
Also seen as
UTF-8 encoding: DF A5 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.229.
- Address
- 0.0.7.229
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.229
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 2021 first appears in π at position 4,351 of the decimal expansion (the 4,351ordinal-suffix:st 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.