1189
A0 paper is 1,189 mm tall.
- Odd
- Composite
Where 1189 fits
Why 1189 is special
1,189 divided by 841 is the square root of two to four decimal places, and 841 multiplied by 1,189 is within a fraction of a percent of one million square millimetres — one square metre, by construction.
Same number, different meanings
How 1189 is understood across different contexts — never implying one meaning because of another.
- Mathematics
1,189 divided by 841 is the square root of two to four decimal places, and 841 multiplied by 1,189 is within a fraction of a percent of one million square millimetres — one square metre, by construction.
- Everyday life
841 by 1,189 mm is a square metre with the sides in the square-root-of-two ratio. Both figures are rounded to whole millimetres, which is why the area is a fraction under a square metre rather than exactly one.
- Law & regulation
English law defines 'time immemorial' as beginning at Richard I's accession in 1189. A cut-off set in 1275 for administrative convenience is still cited in modern arguments about ancient rights of way.
Factors & digit properties
- Divisors (4)
- 1, 29, 41, 1189
- Prime factorisation
- 29 × 41
- Digit sum
- 19
- Digital root
- 1
Representations
- Decimal
- 1189
- Binary
- 10010100101
- Octal
- 2245
- Hexadecimal
- 4a5
- Roman numeral
- MCLXXXIX
- Scientific notation
- 1.189 × 10^3
Other mathematical patterns
- Deficient number
- Semiprime
- Lucky number (mathematical sieve)
Related numbers & connections
841 by 1,189 mm is one square metre with sides in the square-root-of-two ratio, which is the definition every other A size is derived from.
View 841 →Other connections
- is associated with841
why?
Strength 0.50, confidence "high".
Everyday life
841 by 1,189 mm is a square metre with the sides in the square-root-of-two ratio. Both figures are rounded to whole millimetres, which is why the area is a fraction under a square metre rather than exactly one.
DocumentedEveryday lifeGeography: International outside North America
Law & regulation
English law defines 'time immemorial' as beginning at Richard I's accession in 1189. A cut-off set in 1275 for administrative convenience is still cited in modern arguments about ancient rights of way.
DocumentedLaw & regulationGeography: EnglandPeriod: 1189
Common questions
Is 1189 a prime number?
No, 1189 is not prime.
What are the factors of 1189?
The factors of 1189 are 1, 29, 41, 1189.
What is 1189 in Roman numerals?
1189 in Roman numerals is MCLXXXIX.
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: 3 August 2026