1840
1840 is the year the Penny Black created modern postage.
- Even
- Composite
Where 1840 fits
Why 1840 is special
Prepayment by the sender, at one price regardless of distance, replaced a system where the recipient paid according to how far the letter had come. Every postal system in the world adopted the model within decades.
Factors & digit properties
- Divisors (20)
- 1, 2, 4, 5, 8, 10, 16, 20, 23, 40, 46, 80, 92, 115, 184, 230, 368, 460, 920, 1840
- Prime factorisation
- 2^4 × 5 × 23
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 1840
- Binary
- 11100110000
- Octal
- 3460
- Hexadecimal
- 730
- Roman numeral
- MDCCCXL
- Scientific notation
- 1.840 × 10^3
Other mathematical patterns
- Abundant number
Related numbers & connections
Mail coaches from 1784 made letter delivery predictable, and the Penny Black in 1840 made it cheap and prepaid. Reliability came first and affordability second.
View 1784 →Other connections
- developed from1784
why?
Strength 0.50, confidence "high".
Everyday life
The Penny Black established prepayment by the sender at a single price regardless of distance, replacing a system where the recipient paid by the mile. Every postal system in the world adopted the model within a few decades.
DocumentedEveryday lifeGeography: United KingdomPeriod: 1840
Common questions
Is 1840 a prime number?
No, 1840 is not prime.
What are the factors of 1840?
The factors of 1840 are 1, 2, 4, 5, 8, 10, 16, 20, 23, 40, 46, 80, 92, 115, 184, 230, 368, 460, 920, 1840.
What is 1840 in Roman numerals?
1840 in Roman numerals is MDCCCXL.
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