39
39 is the atomic number of yttrium, and the number in John Buchan's novel 'The Thirty-Nine Steps'.
- Odd
- Composite
Where 39 fits
Why 39 is special
39's cultural recognition comes almost entirely from Buchan's 1915 novel and Hitchcock's later film adaptation, not from any mathematical property.
Same number, different meanings
How 39 is understood across different contexts — never implying one meaning because of another.
- Mathematics
39's cultural recognition comes almost entirely from Buchan's 1915 novel and Hitchcock's later film adaptation, not from any mathematical property.
- Science
39 is the atomic number of yttrium.
- Media & popular culture
'The Thirty-Nine Steps' — John Buchan's 1915 novel, later a well-known Alfred Hitchcock film — gave its title number lasting recognition in British popular culture.
Factors & digit properties
- Divisors (4)
- 1, 3, 13, 39
- Prime factorisation
- 3 × 13
- Digit sum
- 12
- Digital root
- 3
Representations
- Decimal
- 39
- Binary
- 100111
- Octal
- 47
- Hexadecimal
- 27
- Roman numeral
- XXXIX
- Scientific notation
- 3.900 × 10^1
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
13 is a factor of 39 (13 × 3 = 39).
View 13 →Science
39 is the atomic number of yttrium.
DocumentedScience
Media & popular culture
'The Thirty-Nine Steps' — John Buchan's 1915 novel, later a well-known Alfred Hitchcock film — gave its title number lasting recognition in British popular culture.
DocumentedMedia & popular culture
Common questions
Is 39 a prime number?
No, 39 is not prime.
What are the factors of 39?
The factors of 39 are 1, 3, 13, 39.
What is 39 in Roman numerals?
39 in Roman numerals is XXXIX.
About this page's data
Mathematical facts:computed directly from the number's value — nothing to source or verify externally.
Contextual records: 2 reviewer-confirmed records, sourced and reviewed before publication.
Last reviewed: 15 July 2026