1686
1686 is the year the first recorded description of a fossil dinosaur bone was published.
- Even
- Composite
Where 1686 fits
Why 1686 is special
It was interpreted as the thigh bone of a giant human. The concept of extinct species did not exist, so the evidence was fitted to the framework available.
1686 connects to:
- historical years — appears in
- 1749 — contrasts with
Same number, different meanings
How 1686 is understood across different contexts — never implying one meaning because of another.
- Mathematics
It was interpreted as the thigh bone of a giant human. The concept of extinct species did not exist, so the evidence was fitted to the framework available.
- History
In 1686, Edmond Halley published the first meteorological chart, mapping the trade winds (England).
- Science
A bone described in 1686 is now recognised as dinosaur. Without a concept of extinction, the only available reading was a giant human, which is what was published.
1686 is part of
Factors & digit properties
- Divisors (8)
- 1, 2, 3, 6, 281, 562, 843, 1686
- Prime factorisation
- 2 × 3 × 281
- Digit sum
- 21
- Digital root
- 3
Representations
- Decimal
- 1686
- Scientific notation
- 1.686 × 10^3
Roman numerals
M D C L X X X V I
Binary
1 1 0 1 0 0 1 0 1 1 0
1 × 1,024 + 1 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 1 × 2 + 0 × 1 = 1,686
Octal
3 2 2 6
3 × 512 + 2 × 64 + 2 × 8 + 6 × 1 = 1,686
Hexadecimal
6 9 6
6 × 256 + 9 × 16 + 6 × 1 = 1,686
Read as powers of two: 1,024 + 512 + 128 + 16 + 4 + 2 = 1,686.
In historical numeral systems
Egyptian
1 lotus, 6 coils of rope, 8 hobbles, 6 strokes
1 × 1,000 + 6 × 100 + 8 × 10 + 6 × 1 = 1,686. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 corner wedges + 8 vertical wedges (sixties place), 6 vertical wedges (units place)
28 × 60 + 6 = 1686. 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
- Abundant number
Related numbers & connections
1686 is a year in the 17th century, in the 1680s.
A fossil bone described in 1686 was read as a giant human's because extinction was not a available concept. Buffon's natural history from 1749 proposed an Earth old enough for species to change.
View 1749 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- contrasts with1749
why?
Strength 0.50, confidence "high".
History
In 1686, Edmond Halley published the first meteorological chart, mapping the trade winds (England).
DocumentedHistoryGeography: EnglandPeriod: 1686
Science
A bone described in 1686 is now recognised as dinosaur. Without a concept of extinction, the only available reading was a giant human, which is what was published.
DocumentedScienceGeography: EnglandPeriod: 1686
Common questions
Is 1686 a prime number?
No, 1686 is not prime.
What are the factors of 1686?
The factors of 1686 are 1, 2, 3, 6, 281, 562, 843, 1686.
What is 1686 in Roman numerals?
1686 in Roman numerals is MDCLXXXVI.
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