1365
NGC 1365 is the Great Barred Spiral.
- Odd
- Composite
Where 1365 fits
Why 1365 is special
Its bar is long enough that gas funnelled along it feeds an active nucleus, which is the clearest observed case of a bar driving a black hole.
Same number, different meanings
How 1365 is understood across different contexts — never implying one meaning because of another.
- Mathematics
Its bar is long enough that gas funnelled along it feeds an active nucleus, which is the clearest observed case of a bar driving a black hole.
- History
In 1365, the University of Vienna was founded (Central Europe).
- Science
NGC 1365 in the Fornax cluster has a prominent bar and an active galactic nucleus, and is a standard case for studying bar-driven gas inflow.
1365 is part of
Factors & digit properties
- Divisors (16)
- 1, 3, 5, 7, 13, 15, 21, 35, 39, 65, 91, 105, 195, 273, 455, 1365
- Prime factorisation
- 3 × 5 × 7 × 13
- Digit sum
- 15
- Digital root
- 6
Representations
- Decimal
- 1365
- Scientific notation
- 1.365 × 10^3
Roman numerals
M C C C L X V
Binary
1 0 1 0 1 0 1 0 1 0 1
1 × 1,024 + 0 × 512 + 1 × 256 + 0 × 128 + 1 × 64 + 0 × 32 + 1 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 1,365
Octal
2 5 2 5
2 × 512 + 5 × 64 + 2 × 8 + 5 × 1 = 1,365
Hexadecimal
5 5 5
5 × 256 + 5 × 16 + 5 × 1 = 1,365
Read as powers of two: 1,024 + 256 + 64 + 16 + 4 + 1 = 1,365.
In historical numeral systems
Egyptian
1 lotus, 3 coils of rope, 6 hobbles, 5 strokes
1 × 1,000 + 3 × 100 + 6 × 10 + 5 × 1 = 1,365. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 corner wedges + 2 vertical wedges (sixties place), 4 corner wedges + 5 vertical wedges (units place)
22 × 60 + 45 = 1365. Places are separated by a space on the tablet, with the higher place written first.
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
- Harshad (Niven) number
- Lucky number (mathematical sieve)
Related numbers & connections
Both are barred spirals used as reference examples, one for clean morphology and one for a bar visibly feeding a nucleus.
View 1300 →Both show gas driven inward along a bar, one feeding an active nucleus and one piling up in a star-forming ring.
View 1097 →History
In 1365, the University of Vienna was founded (Central Europe).
DocumentedHistoryGeography: Central EuropePeriod: 1365
Science
NGC 1365 in the Fornax cluster has a prominent bar and an active galactic nucleus, and is a standard case for studying bar-driven gas inflow.
DocumentedSciencePeriod: 1826–
Common questions
Is 1365 a prime number?
No, 1365 is not prime.
What are the factors of 1365?
The factors of 1365 are 1, 3, 5, 7, 13, 15, 21, 35, 39, 65, 91, 105, 195, 273, 455, 1365.
What is 1365 in Roman numerals?
1365 in Roman numerals is MCCCLXV.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026