53
53 is a prime number and the atomic number of iodine, essential to thyroid function.
- Odd
- Prime
Where 53 fits
Why 53 is special
53's biology tie (iodine) is more notable than its unremarkable mathematical profile as an ordinary two-digit prime.
53 is part of
Factors & digit properties
- Divisors (2)
- 1, 53
- Prime factorisation
- 53
- Digit sum
- 8
- Digital root
- 8
Representations
- Decimal
- 53
- Binary
- 110101
- Octal
- 65
- Hexadecimal
- 35
- Roman numeral
- LIII
- Scientific notation
- 5.300 × 10^1
Other mathematical patterns
- Deficient number
- Sophie Germain prime
Related numbers & connections
53 and 52 are consecutive integers.
View 52 →Nearby in a sequence
- is adjacent to52
why?
Strength 0.50, confidence "high".
Science
53 is the atomic number of iodine, essential to thyroid function.
DocumentedScience
Mathematics
53 is prime — the 16th prime number.
DocumentedMathematics
Common questions
Is 53 a prime number?
Yes, 53 is prime — it has exactly two positive divisors: 1 and itself.
What are the factors of 53?
The factors of 53 are 1, 53.
What is 53 in Roman numerals?
53 in Roman numerals is LIII.
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