343
Sound travels at about 343 metres per second in air at 20 degrees Celsius.
Where 343 fits
Why 343 is special
Speed depends on temperature, not on air pressure or altitude directly, which is why the figure must be quoted with a temperature. It is also why counting the seconds between lightning and thunder gives roughly one kilometre for every three seconds.
343 is part of
Factors & digit properties
- Divisors (4)
- 1, 7, 49, 343
- Prime factorisation
- 7^3
- Digit sum
- 10
- Digital root
- 1
Representations
- Decimal
- 343
- Binary
- 101010111
- Octal
- 527
- Hexadecimal
- 157
- Roman numeral
- CCCXLIII
- Scientific notation
- 3.430 × 10^2
Other mathematical patterns
- Palindromic number
- Deficient number
- Powerful number
Related numbers & connections
Both describe air at defined conditions. The speed of sound depends on temperature rather than pressure directly, which is why 343 m/s must be quoted with a temperature and 1,013 hPa with an altitude.
View 1013 →Other connections
- is associated with1013
why?
Strength 0.50, confidence "high".
Science
Sound covers about 343 metres per second in air at 20 degrees Celsius, so roughly three seconds between lightning and thunder means about a kilometre. The speed depends on temperature rather than on pressure or altitude directly, which is why the figure is meaningless without one.
DocumentedScience
Common questions
Is 343 a prime number?
No, 343 is not prime.
What are the factors of 343?
The factors of 343 are 1, 7, 49, 343.
What is 343 in Roman numerals?
343 in Roman numerals is CCCXLIII.
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