951
951 Gaspra was the first asteroid photographed close up.
- Odd
- Composite
Where 951 fits
Why 951 is special
Galileo passed it in 1991 on the way to Jupiter, and the images ended centuries of asteroids being nothing but moving points of light.
Factors & digit properties
- Divisors (4)
- 1, 3, 317, 951
- Prime factorisation
- 3 × 317
- Digit sum
- 15
- Digital root
- 6
Representations
- Decimal
- 951
- Binary
- 1110110111
- Octal
- 1667
- Hexadecimal
- 3b7
- Roman numeral
- CMLI
- Scientific notation
- 9.510 × 10^2
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
Gaspra was the first asteroid photographed close up, six years before Eros became the first orbited and landed on.
View 433 →Science
The Galileo spacecraft flew past 951 Gaspra in October 1991, returning the first close-range images of an asteroid and showing an irregular, heavily cratered body.
DocumentedSciencePeriod: 1916–
Common questions
Is 951 a prime number?
No, 951 is not prime.
What are the factors of 951?
The factors of 951 are 1, 3, 317, 951.
What is 951 in Roman numerals?
951 in Roman numerals is CMLI.
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