80
80 is the atomic number of mercury — the only metal liquid at room temperature — and the number in Jules Verne's 'Around the World in Eighty Days'.
- Even
- Composite
Where 80 fits
Why 80 is special
80 connects a genuine chemistry superlative (mercury's liquidity) to Phileas Fogg's famous wagered journey in Verne's 1873 adventure novel.
Same number, different meanings
How 80 is understood across different contexts — never implying one meaning because of another.
- Mathematics
80 connects a genuine chemistry superlative (mercury's liquidity) to Phileas Fogg's famous wagered journey in Verne's 1873 adventure novel.
- Science
80 is the atomic number of mercury, the only metal that is liquid at room temperature.
- Media & popular culture
'Around the World in Eighty Days' — Jules Verne's 1873 novel — made 80 a recognisable adventure-story number, referring to Phileas Fogg's wagered round-the-world journey.
Factors & digit properties
- Divisors (10)
- 1, 2, 4, 5, 8, 10, 16, 20, 40, 80
- Prime factorisation
- 2^4 × 5
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 80
- Binary
- 1010000
- Octal
- 120
- Hexadecimal
- 50
- Roman numeral
- LXXX
- Scientific notation
- 8.000 × 10^1
Other mathematical patterns
- Abundant number
- Harshad (Niven) number
Related numbers & connections
20 is a factor of 80 (20 × 4 = 80).
View 20 →79 and 80 are consecutive integers.
View 79 →Science
80 is the atomic number of mercury, the only metal that is liquid at room temperature.
DocumentedScience
Media & popular culture
'Around the World in Eighty Days' — Jules Verne's 1873 novel — made 80 a recognisable adventure-story number, referring to Phileas Fogg's wagered round-the-world journey.
DocumentedMedia & popular culture
Common questions
Is 80 a prime number?
No, 80 is not prime.
What are the factors of 80?
The factors of 80 are 1, 2, 4, 5, 8, 10, 16, 20, 40, 80.
What is 80 in Roman numerals?
80 in Roman numerals is LXXX.
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