1155
1155 is a year in the 12th century. Frederick Barbarossa was crowned emperor at Rome (Europe).
- Odd
- Composite
Where 1155 fits
Why 1155 is special
1155 has a profile because of what happened in it rather than because of any property of the number: Frederick Barbarossa was crowned emperor at Rome (Europe).
1155 is part of
Factors & digit properties
- Divisors (16)
- 1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 77, 105, 165, 231, 385, 1155
- Prime factorisation
- 3 × 5 × 7 × 11
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 1155
- Scientific notation
- 1.155 × 10^3
Roman numerals
M C L V
Binary
1 0 0 1 0 0 0 0 0 1 1
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 1,155
Octal
2 2 0 3
2 × 512 + 2 × 64 + 0 × 8 + 3 × 1 = 1,155
Hexadecimal
4 8 3
4 × 256 + 8 × 16 + 3 × 1 = 1,155
Read as powers of two: 1,024 + 128 + 2 + 1 = 1,155.
In historical numeral systems
Egyptian
1 lotus, 1 coil of rope, 5 hobbles, 5 strokes
1 × 1,000 + 1 × 100 + 5 × 10 + 5 × 1 = 1,155. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
1 corner wedge + 9 vertical wedges (sixties place), 1 corner wedge + 5 vertical wedges (units place)
19 × 60 + 15 = 1155. 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
- Lucky number (mathematical sieve)
Related numbers & connections
1155 is a year in the 12th century, in the 1150s.
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1155, Frederick Barbarossa was crowned emperor at Rome (Europe).
DocumentedHistoryGeography: EuropePeriod: 1155
Common questions
Is 1155 a prime number?
No, 1155 is not prime.
What are the factors of 1155?
The factors of 1155 are 1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 77, 105, 165, 231, 385, 1155.
What is 1155 in Roman numerals?
1155 in Roman numerals is MCLV.
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