491
K. 491 is the C minor piano concerto.
- Odd
- Prime
Where 491 fits
Why 491 is special
It uses the largest orchestra of any Mozart concerto, including both oboes and clarinets, which is a combination he otherwise avoided.
491 is part of
Factors & digit properties
- Divisors (2)
- 1, 491
- Prime factorisation
- 491
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 491
- Binary
- 111101011
- Octal
- 753
- Hexadecimal
- 1eb
- Roman numeral
- CDXCI
- Scientific notation
- 4.910 × 10^2
Other mathematical patterns
- Deficient number
- Sophie Germain prime
Related numbers & connections
Mozart's two minor-key piano concertos, one with Beethoven's cadenzas and one with his largest orchestra.
View 466 →The pair are routinely programmed together as the minor-key concertos.
View 466 →Media & popular culture
K. 491 employs Mozart's largest concerto orchestra, uniquely including both oboes and clarinets alongside flute, bassoons, horns, trumpets and timpani.
DocumentedMedia & popular cultureGeography: AustriaPeriod: 1786
Common questions
Is 491 a prime number?
Yes, 491 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 491?
The factors of 491 are 1, 491.
What is 491 in Roman numerals?
491 in Roman numerals is CDXCI.
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