1187
1187 is the year Saladin retook Jerusalem.
- Odd
- Prime
Where 1187 fits
Why 1187 is special
His terms after the siege — ransom rather than massacre — contrasted sharply with the crusader capture of 1099 and were noted by Christian chroniclers at the time. The recapture triggered the Third Crusade.
1187 is part of
Factors & digit properties
- Divisors (2)
- 1, 1187
- Prime factorisation
- 1187
- Digit sum
- 17
- Digital root
- 8
Representations
- Decimal
- 1187
- Scientific notation
- 1.187 × 10^3
Roman numerals
M C L X X X V I I
Binary
1 0 0 1 0 1 0 0 0 1 1
1 × 1,024 + 0 × 512 + 0 × 256 + 1 × 128 + 0 × 64 + 1 × 32 + 0 × 16 + 0 × 8 + 0 × 4 + 1 × 2 + 1 × 1 = 1,187
Octal
2 2 4 3
2 × 512 + 2 × 64 + 4 × 8 + 3 × 1 = 1,187
Hexadecimal
4 a 3
4 × 256 + a × 16 + 3 × 1 = 1,187
Read as powers of two: 1,024 + 128 + 32 + 2 + 1 = 1,187.
In historical numeral systems
Egyptian
1 lotus, 1 coil of rope, 8 hobbles, 7 strokes
1 × 1,000 + 1 × 100 + 8 × 10 + 7 × 1 = 1,187. 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 + 7 vertical wedges (units place)
19 × 60 + 47 = 1187. 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
- Safe prime
Related numbers & connections
1187 is a year in the 12th century, in the 1180s.
Richard I took Acre in 1191 on the Third Crusade, called after Saladin retook Jerusalem in 1187.
View 1191 →History
In 1187, Saladin destroyed the crusader army at Hattin and recovered Jerusalem (Levant).
DocumentedHistoryGeography: LevantPeriod: 1187Saladin allowed the population of Jerusalem to ransom themselves in 1187 rather than putting it to the sword. European chronicles recorded the contrast with the crusader capture of 1099, which is unusual testimony to come from an opponent.
DocumentedHistoryGeography: JerusalemPeriod: 1187
Common questions
Is 1187 a prime number?
Yes, 1187 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 1187?
The factors of 1187 are 1, 1187.
What is 1187 in Roman numerals?
1187 in Roman numerals is MCLXXXVII.
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: 15 July 2026