MrAl is quite correct about 8000 kHz.
However I would like to clarify/expand on very low frequencies.
"Radio" is generally considered to start at 10kHz.
If you look at the frequency assignment plans as published by OFCOM (UK) or the FCC (USA) they start at 10kHz.
I have a receiver which works from 10kHz to 30Mhz, I would not consider it anything particularly special, but then again the average man in the street would think that it was something "liberated" from a very hi-tech place if he saw it.
Frequency ranges are officially named as:
Very low frequency (VLF) 3 to 30kHz
Low frequency (LF) 30 to 300kHz
Medium frequency (MF) 300kHz to 3 Mhz
High frequency (HF) 3 to 30 Mhz
Very high frequency (VHF) 30 to 300Mhz
Ultra high frequency (UHF) 300 to 3000Mhz
Super High frequency (SHF) 3000 to 30,000Mhz
There are others, above and below these ranges, look here:
https://en.wikipedia.org/wiki/Radio_spectrum
In terms of the good old "wavelength" designators for broadcast radio:
Long wave 2000 to 1000 metres (150 to 300khz)
Medium wave 550 to 180 metres (545 to 1660 khz)
Short wave 100 to 10 metres (3 to 30 Mhz)
JimB