553
The CN Tower is 553 metres tall.
- Odd
- Composite
Where 553 fits
Why 553 is special
It held the record for tallest free-standing structure from 1975 to 2007. Its purpose was practical: Toronto's new skyscrapers were blocking broadcast signals, so a taller transmitter was needed.
Factors & digit properties
- Divisors (4)
- 1, 7, 79, 553
- Prime factorisation
- 7 × 79
- Digit sum
- 13
- Digital root
- 4
Representations
- Decimal
- 553
- Binary
- 1000101001
- Octal
- 1051
- Hexadecimal
- 229
- Roman numeral
- DLIII
- Scientific notation
- 5.530 × 10^2
Other mathematical patterns
- Deficient number
- Semiprime
- Lucky number (mathematical sieve)
Related numbers & connections
The Burj Khalifa and the CN Tower held different records — tallest structure and tallest free-standing structure — and the distinction between categories is exactly what makes height records contentious.
View 828 →Other connections
- contrasts with828
why?
Strength 0.50, confidence "high".
Technology & computing
The CN Tower was built in 1975 because downtown skyscrapers were interfering with broadcast reception. A structure that held a world record for 32 years exists to solve a radio-propagation problem.
DocumentedTechnology & computingGeography: Toronto, CanadaPeriod: 1975–2007
Common questions
Is 553 a prime number?
No, 553 is not prime.
What are the factors of 553?
The factors of 553 are 1, 7, 79, 553.
What is 553 in Roman numerals?
553 in Roman numerals is DLIII.
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