2006
2006 is the year Pluto was reclassified as a dwarf planet.
- Even
- Composite
Where 2006 fits
Why 2006 is special
The vote defined a planet as needing to have cleared its orbital neighbourhood, which Pluto has not. The decision was made by a fraction of the astronomers present on the final day of a conference and remains contested.
Same number, different meanings
How 2006 is understood across different contexts — never implying one meaning because of another.
- Mathematics
The vote defined a planet as needing to have cleared its orbital neighbourhood, which Pluto has not. The decision was made by a fraction of the astronomers present on the final day of a conference and remains contested.
- History
In 2006, the International Astronomical Union adopted a definition of 'planet' that reclassified Pluto as a dwarf planet.
- Science
The IAU's planet definition was adopted on the last day of its 2006 assembly by several hundred of the thousands of members. Objections have continued since, and the underlying issue — that Pluto is one of many similar bodies — is not in dispute even where the definition is.
2006 is part of
Factors & digit properties
- Divisors (8)
- 1, 2, 17, 34, 59, 118, 1003, 2006
- Prime factorisation
- 2 × 17 × 59
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 2006
- Scientific notation
- 2.006 × 10^3
Roman numerals
M M V I
Binary
1 1 1 1 1 0 1 0 1 1 0
1 × 1,024 + 1 × 512 + 1 × 256 + 1 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 2,006
Octal
3 7 2 6
3 × 512 + 7 × 64 + 2 × 8 + 6 × 1 = 2,006
Hexadecimal
7 d 6
7 × 256 + d × 16 + 6 × 1 = 2,006
Read as powers of two: 1,024 + 512 + 256 + 128 + 64 + 16 + 4 + 2 = 2,006.
In historical numeral systems
Egyptian
2 lotuses, 6 strokes
2 × 1,000 + 6 × 1 = 2,006. 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), 2 corner wedges + 6 vertical wedges (units place)
33 × 60 + 26 = 2006. 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
Related numbers & connections
2006 is a year in the 21st century, in the 2000s.
Pluto was reclassified in 2006 by a partial vote and the first black hole image was published in 2019 by a global collaboration. Both are cases of astronomy's conclusions resting on how its institutions work.
View 2019 →History
In 2006, the International Astronomical Union adopted a definition of 'planet' that reclassified Pluto as a dwarf planet.
DocumentedHistoryGeography: globalPeriod: 2006
Science
The IAU's planet definition was adopted on the last day of its 2006 assembly by several hundred of the thousands of members. Objections have continued since, and the underlying issue — that Pluto is one of many similar bodies — is not in dispute even where the definition is.
DocumentedSciencePeriod: 2006
Common questions
Is 2006 a prime number?
No, 2006 is not prime.
What are the factors of 2006?
The factors of 2006 are 1, 2, 17, 34, 59, 118, 1003, 2006.
What is 2006 in Roman numerals?
2006 in Roman numerals is MMVI.
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