2019
2019 is the year the first image of a black hole was published.
- Odd
- Composite
Where 2019 fits
Why 2019 is special
Eight radio telescopes were combined into an Earth-sized virtual instrument, producing so much data it was shipped physically on hard drives rather than transmitted. The result confirmed predictions made a century earlier.
2019 is part of
Factors & digit properties
- Divisors (4)
- 1, 3, 673, 2019
- Prime factorisation
- 3 × 673
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 2019
- Scientific notation
- 2.019 × 10^3
Roman numerals
M M X I X
MMXIX uses the subtractive pair IX: one before ten — ten minus one.
Binary
1 1 1 1 1 1 0 0 0 1 1
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 2,019
Octal
3 7 4 3
3 × 512 + 7 × 64 + 4 × 8 + 3 × 1 = 2,019
Hexadecimal
7 e 3
7 × 256 + e × 16 + 3 × 1 = 2,019
Read as powers of two: 1,024 + 512 + 256 + 128 + 64 + 32 + 2 + 1 = 2,019.
In historical numeral systems
Egyptian
2 lotuses, 1 hobble, 9 strokes
2 × 1,000 + 1 × 10 + 9 × 1 = 2,019. 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), 3 corner wedges + 9 vertical wedges (units place)
33 × 60 + 39 = 2019. 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
- Happy number
- Semiprime
- Lucky number (mathematical sieve)
Related numbers & connections
2019 is a year in the 21st century, in the 2010s.
A comet panic built on a real detection, and a black hole image built on data too large to transmit. Both show a true technical detail reaching the public in a form its discoverers did not choose.
View 1910 →Science
In 2019, the first image of a black hole was published by the Event Horizon Telescope.
DocumentedScienceGeography: globalPeriod: 2019Eight radio telescopes were combined into an Earth-sized virtual instrument to image a black hole. The volume of data was too large to transmit, so it was flown on physical drives. The result matched predictions made a century earlier.
DocumentedSciencePeriod: April 2019
Common questions
Is 2019 a prime number?
No, 2019 is not prime.
What are the factors of 2019?
The factors of 2019 are 1, 3, 673, 2019.
What is 2019 in Roman numerals?
2019 in Roman numerals is MMXIX. IX is subtractive: one before ten — ten minus one. Written additively it would be MMXVIIII, which Roman inscriptions used freely — the strict subtractive form is a later convention.
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