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.
1189 connects to:
- historical years — appears in
- 841 — is associated with
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.
- History
In 1189, the Third Crusade set out in response to the loss of Jerusalem (Levant).
- 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.
1189 is part of
Factors & digit properties
- Divisors (4)
- 1, 29, 41, 1189
- Prime factorisation
- 29 × 41
- Digit sum
- 19
- Digital root
- 1
Representations
- Decimal
- 1189
- Scientific notation
- 1.189 × 10^3
Roman numerals
M C L X X X I X
MCLXXXIX uses the subtractive pair IX: one before ten — ten minus one.
Binary
1 0 0 1 0 1 0 0 1 0 1
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 1 × 4 + 0 × 2 + 1 × 1 = 1,189
Octal
2 2 4 5
2 × 512 + 2 × 64 + 4 × 8 + 5 × 1 = 1,189
Hexadecimal
4 a 5
4 × 256 + a × 16 + 5 × 1 = 1,189
Read as powers of two: 1,024 + 128 + 32 + 4 + 1 = 1,189.
In historical numeral systems
Egyptian
1 lotus, 1 coil of rope, 8 hobbles, 9 strokes
1 × 1,000 + 1 × 100 + 8 × 10 + 9 × 1 = 1,189. 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), 4 corner wedges + 9 vertical wedges (units place)
19 × 60 + 49 = 1189. 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
- Semiprime
- Lucky number (mathematical sieve)
Related numbers & connections
1189 is a year in the 12th century, in the 1180s.
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 →Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
Other connections
- is associated with841
why?
Strength 0.50, confidence "high".
History
In 1189, the Third Crusade set out in response to the loss of Jerusalem (Levant).
DocumentedHistoryGeography: LevantPeriod: 1189
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. IX is subtractive: one before ten — ten minus one. Written additively it would be MCLXXXVIIII, which Roman inscriptions used freely — the strict subtractive form is a later convention.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 3 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026