What is the wavelength of radiation at a frequency of 543.3Hz?

For a frequency f in air with the speed of sound of c = 343 meters per second the wavelength lambda = c / f. A frequency of 543.3 Hz meters equals a wavelength of 0.6313 meters. There is a useful calculator for converting wavelength to frequency and vice versa. Scroll down to related links and look at "Acoustic waves or sound waves in air".