342
IC 342 is the Hidden Galaxy.
- Even
- Composite
Where 342 fits
Why 342 is special
It would be among the brightest galaxies in the sky if it were not directly behind the plane of the Milky Way, where dust absorbs most of its light.
Factors & digit properties
- Divisors (12)
- 1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 342
- Prime factorisation
- 2 × 3^2 × 19
- Digit sum
- 9
- Digital root
- 9
Representations
- Decimal
- 342
- Binary
- 101010110
- Octal
- 526
- Hexadecimal
- 156
- Roman numeral
- CCCXLII
- Scientific notation
- 3.420 × 10^2
Other mathematical patterns
- Abundant number
- Harshad (Niven) number
Related numbers & connections
Both are large spirals close to the galactic plane, where Milky Way dust dims what would otherwise be prominent.
View 6946 →Other connections
- is associated with6946
why?
Strength 0.50, confidence "high".
Science
IC 342 is a large spiral galaxy close to the galactic plane. Interstellar dust in the Milky Way substantially dims it, which is why it was not catalogued earlier.
DocumentedSciencePeriod: 1892–
Common questions
Is 342 a prime number?
No, 342 is not prime.
What are the factors of 342?
The factors of 342 are 1, 2, 3, 6, 9, 18, 19, 38, 57, 114, 171, 342.
What is 342 in Roman numerals?
342 in Roman numerals is CCCXLII.
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