2021
2021 is the year the James Webb Space Telescope launched.
- Odd
- Composite
Where 2021 fits
Why 2021 is special
It launched on Christmas Day after roughly twenty-five years of development and repeated delays, and had to unfold itself through hundreds of single-point-of-failure steps with no possibility of repair. All of them worked.
Same number, different meanings
How 2021 is understood across different contexts — never implying one meaning because of another.
- Mathematics
It launched on Christmas Day after roughly twenty-five years of development and repeated delays, and had to unfold itself through hundreds of single-point-of-failure steps with no possibility of repair. All of them worked.
- History
In 2021, the James Webb Space Telescope was launched.
- Science
The James Webb Space Telescope launched on Christmas Day 2021 after around twenty-five years of development, then unfolded itself through hundreds of steps with no possibility of repair and no redundancy for most of them. Every one succeeded.
2021 is part of
Factors & digit properties
- Divisors (4)
- 1, 43, 47, 2021
- Prime factorisation
- 43 × 47
- Digit sum
- 5
- Digital root
- 5
Representations
- Decimal
- 2021
- Scientific notation
- 2.021 × 10^3
Roman numerals
M M X X I
Binary
1 1 1 1 1 1 0 0 1 0 1
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 2,021
Octal
3 7 4 5
3 × 512 + 7 × 64 + 4 × 8 + 5 × 1 = 2,021
Hexadecimal
7 e 5
7 × 256 + e × 16 + 5 × 1 = 2,021
Read as powers of two: 1,024 + 512 + 256 + 128 + 64 + 32 + 4 + 1 = 2,021.
In historical numeral systems
Egyptian
2 lotuses, 2 hobbles, 1 stroke
2 × 1,000 + 2 × 10 + 1 × 1 = 2,021. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
3 corner wedges + 3 vertical wedges (sixties place), 4 corner wedges + 1 vertical wedge (units place)
33 × 60 + 41 = 2021. Places are separated by a space on the tablet, with the higher place written first.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
2021 is a year in the 21st century, in the 2020s.
Hubble launched in 1990 and Webb in 2021. Webb observes in the infrared and had to unfold itself after launch with no possibility of the repair missions Hubble depended on.
View 1990 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- developed from1990
why?
Strength 0.50, confidence "high".
History
In 2021, the James Webb Space Telescope was launched.
DocumentedHistoryGeography: globalPeriod: 2021
Science
The James Webb Space Telescope launched on Christmas Day 2021 after around twenty-five years of development, then unfolded itself through hundreds of steps with no possibility of repair and no redundancy for most of them. Every one succeeded.
DocumentedSciencePeriod: 25 December 2021
Common questions
Is 2021 a prime number?
No, 2021 is not prime.
What are the factors of 2021?
The factors of 2021 are 1, 43, 47, 2021.
What is 2021 in Roman numerals?
2021 in Roman numerals is MMXXI.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026