Overview
1087 is a four‑digit natural number that functions both as an abstract integer and as a label for historical years (for example, AD 1087). As a number it sits between 1086 and 1088; as a year it belongs to the High Middle Ages. This entry treats 1087 in mathematical, historical and cultural contexts.
Mathematical properties
In arithmetic terms 1087 is an odd prime number. It is not a square, not a triangular number, and not palindromic in base 10. Common alternate representations include the binary form 10000111111, hexadecimal 0x43F, and Roman numerals MLXXXVII. The sum of its decimal digits is 1 + 0 + 8 + 7 = 16, with a digital root of 7.
- Parity: odd.
- Prime status: prime (no positive divisors other than 1 and itself).
- Binary: 10000111111; Hex: 43F.
Year AD 1087
The year 1087 falls within the period commonly called the High Middle Ages. One widely noted event of that year is the death of William the Conqueror (William I of England), after which his realm was divided between his sons: one inherited the English crown and another the Norman duchy. Political and ecclesiastical life in Western Europe during this era was shaped by feudal structures, church reform movements and ongoing relations between rulers and bishops.
Other contexts and distinctions
Beyond arithmetic and chronology, the numeral 1087 may appear as an identifier in modern catalogues, registers, model numbers or serial codes. In scholarship and reference works, entries headed by 1087 will usually clarify whether they concern the number itself, the historical year AD 1087, or a modern object bearing that number.
When discussing 1087 it is helpful to distinguish clearly whether the subject is the abstract integer (with its algebraic and number‑theoretic properties) or the historical year (with its events and chronology). Both uses are common in encyclopedic and reference contexts.