1842
1842 is the year the Treaty of Nanking ceded Hong Kong to Britain.
- Even
- Composite
Where 1842 fits
Why 1842 is special
It ended the First Opium War, fought to force China to accept opium imports. The treaty is the first of what Chinese historiography calls the unequal treaties.
Factors & digit properties
- Divisors (8)
- 1, 2, 3, 6, 307, 614, 921, 1842
- Prime factorisation
- 2 × 3 × 307
- Digit sum
- 15
- Digital root
- 6
Representations
- Decimal
- 1842
- Binary
- 11100110010
- Octal
- 3462
- Hexadecimal
- 732
- Roman numeral
- MDCCCXLII
- Scientific notation
- 1.842 × 10^3
Other mathematical patterns
- Abundant number
Related numbers & connections
The Treaty of Nanking ceded Hong Kong in 1842 and it was returned in 1997, 155 years later under a framework promising a distinct system for fifty more.
View 1997 →Other connections
- developed from1997
why?
Strength 0.50, confidence "high".
Law & regulation
The Treaty of Nanking ended a war Britain fought to compel China to permit opium imports, and transferred Hong Kong. The framing of the nineteenth century in Chinese national history begins here.
DocumentedLaw & regulationGeography: China and BritainPeriod: 1842
Common questions
Is 1842 a prime number?
No, 1842 is not prime.
What are the factors of 1842?
The factors of 1842 are 1, 2, 3, 6, 307, 614, 921, 1842.
What is 1842 in Roman numerals?
1842 in Roman numerals is MDCCCXLII.
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