86
86 is the atomic number of radon, a radioactive noble gas that can accumulate in buildings, and the number behind American slang 'to 86' something.
- Even
- Composite
Where 86 fits
Why 86 is special
86's slang meaning — to discard, cancel, or refuse service — is documented in US diner and bar culture since the 1930s, though its precise origin is disputed.
Same number, different meanings
How 86 is understood across different contexts — never implying one meaning because of another.
- Mathematics
86's slang meaning — to discard, cancel, or refuse service — is documented in US diner and bar culture since the 1930s, though its precise origin is disputed.
- Science
86 is the atomic number of radon, a radioactive noble gas that can accumulate in buildings from underlying rock and soil.
- Culture
The American slang verb 'to 86' something or someone — meaning to discard, cancel, or refuse service to — is documented in US diner and bar culture from the 1930s, though its exact origin is disputed.
86 is part of
Factors & digit properties
- Divisors (4)
- 1, 2, 43, 86
- Prime factorisation
- 2 × 43
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 86
- Binary
- 1010110
- Octal
- 126
- Hexadecimal
- 56
- Roman numeral
- LXXXVI
- Scientific notation
- 8.600 × 10^1
Other mathematical patterns
- Deficient number
- Happy number
- Semiprime
Related numbers & connections
43 is a factor of 86 (43 × 2 = 86).
View 43 →Mathematically related
- has factor43
why?
Strength 0.50, confidence "high".
Science
86 is the atomic number of radon, a radioactive noble gas that can accumulate in buildings from underlying rock and soil.
DocumentedScience
Culture
The American slang verb 'to 86' something or someone — meaning to discard, cancel, or refuse service to — is documented in US diner and bar culture from the 1930s, though its exact origin is disputed.
DisputedCultureGeography: United States
Common questions
Is 86 a prime number?
No, 86 is not prime.
What are the factors of 86?
The factors of 86 are 1, 2, 43, 86.
What is 86 in Roman numerals?
86 in Roman numerals is LXXXVI.
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