26
26 is the atomic number of iron and the number of letters in the modern English alphabet.
- Even
- Composite
Where 26 fits
Why 26 is special
26 quietly anchors two very different systems: the blood-oxygen chemistry of iron in haemoglobin, and the 26-letter alphabet underlying written English.
Same number, different meanings
How 26 is understood across different contexts — never implying one meaning because of another.
- Mathematics
26 quietly anchors two very different systems: the blood-oxygen chemistry of iron in haemoglobin, and the 26-letter alphabet underlying written English.
- Science
26 is the atomic number of iron, the oxygen-carrying core of haemoglobin in blood.
- Everyday life
The modern English alphabet has 26 letters, from A to Z.
Factors & digit properties
- Divisors (4)
- 1, 2, 13, 26
- Prime factorisation
- 2 × 13
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 26
- Binary
- 11010
- Octal
- 32
- Hexadecimal
- 1a
- Roman numeral
- XXVI
- Scientific notation
- 2.600 × 10^1
Other mathematical patterns
- Deficient number
- Semiprime
Related numbers & connections
13 is a factor of 26 (13 × 2 = 26).
View 13 →Science
26 is the atomic number of iron, the oxygen-carrying core of haemoglobin in blood.
DocumentedScience
Everyday life
The modern English alphabet has 26 letters, from A to Z.
DocumentedEveryday life
Common questions
Is 26 a prime number?
No, 26 is not prime.
What are the factors of 26?
The factors of 26 are 1, 2, 13, 26.
What is 26 in Roman numerals?
26 in Roman numerals is XXVI.
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