524
E524 is sodium hydroxide.
- Even
- Composite
Where 524 fits
Why 524 is special
Caustic soda appears on ingredient lists because it is used to treat olives and to give pretzels their crust, which surprises most readers.
Factors & digit properties
- Divisors (6)
- 1, 2, 4, 131, 262, 524
- Prime factorisation
- 2^2 × 131
- Digit sum
- 11
- Digital root
- 2
Representations
- Decimal
- 524
- Binary
- 1000001100
- Octal
- 1014
- Hexadecimal
- 20c
- Roman numeral
- DXXIV
- Scientific notation
- 5.240 × 10^2
Other mathematical patterns
- Deficient number
Related numbers & connections
Both are additives most readers would not expect to see on a food label at all.
View 570 →Numbers Around Us
- appears alongside570
why?
Strength 0.50, confidence "high".
Everyday life
E524 sodium hydroxide is used as an acidity regulator, in olive curing and in the alkaline bath that produces the characteristic crust and flavour of pretzels.
DocumentedEveryday lifeGeography: European Union and states adopting the E number systemPeriod: 1962–
Common questions
Is 524 a prime number?
No, 524 is not prime.
What are the factors of 524?
The factors of 524 are 1, 2, 4, 131, 262, 524.
What is 524 in Roman numerals?
524 in Roman numerals is DXXIV.
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