1265
1265 is the year of the first English parliament to include commoners.
- Odd
- Composite
Why 1265 is special
Simon de Montfort summoned representatives from towns as well as nobles, while in rebellion against the king. Its origin as a rebel assembly is usually left out of accounts that trace parliamentary democracy to it.
Factors & digit properties
- Divisors (8)
- 1, 5, 11, 23, 55, 115, 253, 1265
- Prime factorisation
- 5 × 11 × 23
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 1265
- Binary
- 10011110001
- Octal
- 2361
- Hexadecimal
- 4f1
- Roman numeral
- MCCLXV
- Scientific notation
- 1.265 × 10^3
Other mathematical patterns
- Deficient number
Law & regulation
The 1265 parliament included burgesses from the towns for the first time and was called by Simon de Montfort while at war with Henry III. Its status as a foundation of representative government sits awkwardly with its origin as an insurgent measure.
DocumentedLaw & regulationGeography: EnglandPeriod: 1265
Common questions
Is 1265 a prime number?
No, 1265 is not prime.
What are the factors of 1265?
The factors of 1265 are 1, 5, 11, 23, 55, 115, 253, 1265.
What is 1265 in Roman numerals?
1265 in Roman numerals is MCCLXV.
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: 3 August 2026