1642
1642 is the year the English Civil War began.
- Even
- Composite
Where 1642 fits
Why 1642 is special
It ended with the trial and execution of a reigning king by his own subjects, which had no European precedent. The republic that followed lasted eleven years before the monarchy returned.
Factors & digit properties
- Divisors (4)
- 1, 2, 821, 1642
- Prime factorisation
- 2 × 821
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 1642
- Binary
- 11001101010
- Octal
- 3152
- Hexadecimal
- 66a
- Roman numeral
- MDCXLII
- Scientific notation
- 1.642 × 10^3
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
The Grand Remonstrance passed by eleven votes in 1641 and the English Civil War began the following year.
View 1641 →History
The conflict beginning in 1642 killed a larger share of the population of the British Isles than the First World War did, executed a king, established a republic, and ended with that king's son on the throne eighteen years later.
DocumentedHistoryGeography: England, Scotland and IrelandPeriod: 1642–1651
Common questions
Is 1642 a prime number?
No, 1642 is not prime.
What are the factors of 1642?
The factors of 1642 are 1, 2, 821, 1642.
What is 1642 in Roman numerals?
1642 in Roman numerals is MDCXLII.
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