1161
1161 is a year in the 12th century. Gunpowder bombs were used at the naval battle of Caishi, among the earliest recorded (China).
- Odd
- Composite
Where 1161 fits
Why 1161 is special
1161 has a profile because of what happened in it rather than because of any property of the number: gunpowder bombs were used at the naval battle of Caishi, among the earliest recorded (China).
1161 is part of
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 27, 43, 129, 387, 1161
- Prime factorisation
- 3^3 × 43
- Digit sum
- 9
- Digital root
- 9
Representations
- Decimal
- 1161
- Scientific notation
- 1.161 × 10^3
Roman numerals
M C L X I
Binary
1 0 0 1 0 0 0 1 0 0 1
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 1,161
Octal
2 2 1 1
2 × 512 + 2 × 64 + 1 × 8 + 1 × 1 = 1,161
Hexadecimal
4 8 9
4 × 256 + 8 × 16 + 9 × 1 = 1,161
Read as powers of two: 1,024 + 128 + 8 + 1 = 1,161.
In historical numeral systems
Egyptian
1 lotus, 1 coil of rope, 6 hobbles, 1 stroke
1 × 1,000 + 1 × 100 + 6 × 10 + 1 × 1 = 1,161. 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), 2 corner wedges + 1 vertical wedge (units place)
19 × 60 + 21 = 1161. 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
Related numbers & connections
1161 is a year in the 12th century, in the 1160s.
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1161, gunpowder bombs were used at the naval battle of Caishi, among the earliest recorded (China).
DocumentedHistoryGeography: ChinaPeriod: 1161
Common questions
Is 1161 a prime number?
No, 1161 is not prime.
What are the factors of 1161?
The factors of 1161 are 1, 3, 9, 27, 43, 129, 387, 1161.
What is 1161 in Roman numerals?
1161 in Roman numerals is MCLXI.
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