7331
NGC 7331 was once called the Milky Way's twin.
- Odd
- Prime
Where 7331 fits
Why 7331 is special
The comparison held until the Milky Way's own bar was confirmed, at which point our galaxy turned out to be a different type from its supposed likeness.
7331 is part of
Factors & digit properties
- Divisors (2)
- 1, 7331
- Prime factorisation
- 7331
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 7331
- Scientific notation
- 7.331 × 10^3
Roman numerals
Roman numerals as modelled here goes up to 3,999.
Binary
1 1 1 0 0 1 0 1 0 0 0 1 1
1 × 4,096 + 1 × 2,048 + 1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 7,331
Octal
1 6 2 4 3
1 × 4,096 + 6 × 512 + 2 × 64 + 4 × 8 + 3 × 1 = 7,331
Hexadecimal
1 c a 3
1 × 4,096 + c × 256 + a × 16 + 3 × 1 = 7,331
Read as powers of two: 4,096 + 2,048 + 1,024 + 128 + 32 + 2 + 1 = 7,331.
In historical numeral systems
Egyptian
7 lotuses, 3 coils of rope, 3 hobbles, 1 stroke
7 × 1,000 + 3 × 100 + 3 × 10 + 1 × 1 = 7,331. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Systems that simply cannot reach this value are left out. Where a script needs a font most readers do not have, the reading is given instead of the glyphs — see number systems for each system in full.
Other mathematical patterns
- Deficient number
- Happy number
- Twin prime
Related numbers & connections
Both have been called twins of the Milky Way, and both comparisons weakened once our own galaxy's bar was confirmed.
View 6744 →Other connections
- contrasts with6744
why?
Strength 0.50, confidence "high".
Science
NGC 7331 is a spiral galaxy long compared to the Milky Way. Confirmation of the Milky Way's central bar reduced the strength of the comparison.
DocumentedSciencePeriod: 1784–
Common questions
Is 7331 a prime number?
Yes, 7331 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 7331?
The factors of 7331 are 1, 7331.
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: 15 July 2026