1289
1289 is a year in the 13th century. Tripoli fell to the Mamluks, leaving Acre the last crusader city (Levant).
- Odd
- Prime
Where 1289 fits
Why 1289 is special
1289 has a profile because of what happened in it rather than because of any property of the number: Tripoli fell to the Mamluks, leaving Acre the last crusader city (Levant).
1289 is part of
Factors & digit properties
- Divisors (2)
- 1, 1289
- Prime factorisation
- 1289
- Digit sum
- 20
- Digital root
- 2
Representations
- Decimal
- 1289
- Scientific notation
- 1.289 × 10^3
Roman numerals
M C C L X X X I X
MCCLXXXIX uses the subtractive pair IX: one before ten — ten minus one.
Binary
1 0 1 0 0 0 0 1 0 0 1
1 × 1,024 + 0 × 512 + 1 × 256 + 0 × 128 + 0 × 64 + 0 × 32 + 0 × 16 + 1 × 8 + 0 × 4 + 0 × 2 + 1 × 1 = 1,289
Octal
2 4 1 1
2 × 512 + 4 × 64 + 1 × 8 + 1 × 1 = 1,289
Hexadecimal
5 0 9
5 × 256 + 0 × 16 + 9 × 1 = 1,289
Read as powers of two: 1,024 + 256 + 8 + 1 = 1,289.
In historical numeral systems
Egyptian
1 lotus, 2 coils of rope, 8 hobbles, 9 strokes
1 × 1,000 + 2 × 100 + 8 × 10 + 9 × 1 = 1,289. The signs are simply repeated and added; where they sit on the line is a matter of layout, not value.
Babylonian
2 corner wedges + 1 vertical wedge (sixties place), 2 corner wedges + 9 vertical wedges (units place)
21 × 60 + 29 = 1289. 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
- Sophie Germain prime
- Twin prime
Related numbers & connections
1289 is a year in the 13th century, in the 1280s.
Numbers Around Us
- appears inHistorical years
why?
Strength 0.50, confidence "high".
History
In 1289, Tripoli fell to the Mamluks, leaving Acre the last crusader city (Levant).
DocumentedHistoryGeography: LevantPeriod: 1289
Common questions
Is 1289 a prime number?
Yes, 1289 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 1289?
The factors of 1289 are 1, 1289.
What is 1289 in Roman numerals?
1289 in Roman numerals is MCCLXXXIX. IX is subtractive: one before ten — ten minus one. Written additively it would be MCCLXXXVIIII, 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: 1 reviewer-confirmed record, sourced and reviewed before publication.
Last reviewed: 15 July 2026