6543
NGC 6543 is the Cat's Eye Nebula.
- Odd
- Composite
Where 6543 fits
Why 6543 is special
It was the first planetary nebula whose spectrum was examined, which showed it was glowing gas rather than a cluster of unresolved stars.
6543 is part of
Factors & digit properties
- Divisors (6)
- 1, 3, 9, 727, 2181, 6543
- Prime factorisation
- 3^2 × 727
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 6543
- Binary
- 1100110001111
- Octal
- 14617
- Hexadecimal
- 198f
- Scientific notation
- 6.543 × 10^3
Other mathematical patterns
- Deficient number
- Happy number
Related numbers & connections
The Helix is close enough to appear large and faint where the Cat's Eye appears small and bright.
View 7293 →Science
William Huggins observed NGC 6543 spectroscopically in 1864 and found emission lines rather than a continuous spectrum, establishing that some nebulae are gaseous.
DocumentedSciencePeriod: 1786–
Common questions
Is 6543 a prime number?
No, 6543 is not prime.
What are the factors of 6543?
The factors of 6543 are 1, 3, 9, 727, 2181, 6543.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 3 August 2026