635
The Ediacaran period began about 635 million years ago.
- Odd
- Composite
Where 635 fits
Why 635 is special
It is the only period of the Precambrian defined by a physical marker in a rock section rather than by a chosen date, which makes it unusual in the geological timescale.
635 is part of
Factors & digit properties
- Divisors (4)
- 1, 5, 127, 635
- Prime factorisation
- 5 × 127
- Digit sum
- 14
- Digital root
- 5
Representations
- Decimal
- 635
- Binary
- 1001111011
- Octal
- 1173
- Hexadecimal
- 27b
- Roman numeral
- DCXXXV
- Scientific notation
- 6.350 × 10^2
Other mathematical patterns
- Deficient number
- Happy number
- Semiprime
Related numbers & connections
One marks where the rock record begins and the other the only Precambrian period with a physical boundary marker.
View 3800 →Science
The Ediacaran, ratified in 2004, begins at the base of a cap carbonate following Marinoan glaciation and is defined by a Global Boundary Stratotype Section and Point in South Australia.
DocumentedScienceGeography: Global; type section in South AustraliaPeriod: ratified 2004
Common questions
Is 635 a prime number?
No, 635 is not prime.
What are the factors of 635?
The factors of 635 are 1, 5, 127, 635.
What is 635 in Roman numerals?
635 in Roman numerals is DCXXXV.
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