1809
1809 is the year Darwin and Lincoln were both born.
- Odd
- Composite
Where 1809 fits
Why 1809 is special
They were born on the same day, 12 February 1809. Both are associated with fundamental challenges to established hierarchy, which is a coincidence people have found hard to leave alone.
Factors & digit properties
- Divisors (8)
- 1, 3, 9, 27, 67, 201, 603, 1809
- Prime factorisation
- 3^3 × 67
- Digit sum
- 18
- Digital root
- 9
Representations
- Decimal
- 1809
- Binary
- 11100010001
- Octal
- 3421
- Hexadecimal
- 711
- Roman numeral
- MDCCCIX
- Scientific notation
- 1.809 × 10^3
Other mathematical patterns
- Deficient number
- Lucky number (mathematical sieve)
Related numbers & connections
Darwin was born in 1809 and published On the Origin of Species in 1859, fifty years later and only because Wallace had reached the same conclusion independently.
View 1859 →Other connections
- is associated with1859
why?
Strength 0.50, confidence "high".
History
Charles Darwin and Abraham Lincoln were born on 12 February 1809, in England and Kentucky. The coincidence has generated a substantial literature that generally concludes it is a coincidence.
DocumentedHistoryPeriod: 12 February 1809
Common questions
Is 1809 a prime number?
No, 1809 is not prime.
What are the factors of 1809?
The factors of 1809 are 1, 3, 9, 27, 67, 201, 603, 1809.
What is 1809 in Roman numerals?
1809 in Roman numerals is MDCCCIX.
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