1681
1681 is the year the dodo was last reliably reported.
Where 1681 fits
Why 1681 is special
Extinction within about a century of European contact made it the standard emblem of human-caused extinction, and 'dead as a dodo' entered the language.
1681 is part of
Factors & digit properties
- Divisors (3)
- 1, 41, 1681
- Prime factorisation
- 41^2
- Digit sum
- 16
- Digital root
- 7
Representations
- Decimal
- 1681
- Binary
- 11010010001
- Octal
- 3221
- Hexadecimal
- 691
- Roman numeral
- MDCLXXXI
- Scientific notation
- 1.681 × 10^3
Other mathematical patterns
- Deficient number
- Powerful number
- Semiprime
Science
The dodo disappeared within roughly a century of Europeans reaching Mauritius, mostly through introduced animals eating its eggs rather than direct hunting. The last credible sighting is around 1681.
DocumentedScienceGeography: MauritiusPeriod: 1681
Common questions
Is 1681 a prime number?
No, 1681 is not prime.
What are the factors of 1681?
The factors of 1681 are 1, 41, 1681.
What is 1681 in Roman numerals?
1681 in Roman numerals is MDCLXXXI.
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