The Sun is incredibly dynamic in the radio frequency range, so there isn't a static value or nice consistent spectrum against which to compare. However, one can show an example figure with ranges of values for reference/comparison. An example is given below from Figure 2 in Cecconi et al. .
Just to clarify some of the terms in the figure, they are defined as: QTN is quasi-thermal noise, AKR is auroral kilometric radiation (similarly the SKR and UKR are the equivalents for Saturn and Uranus, respectively), SW is solar wind, Solar burst is referring to solar radio bursts (discussed below), and LF cutoff is low frequency cutoff, as you may have guessed.
The largest sources of radio noise from the sun are due to solar radio bursts, which come in at least five major flavors (i.e., named Type I, Type II, Type III, Type IV, and Type V). You can see from the cartoon-like image that the range of flux densities from the sun can be rather large, i.e., upwards of eight orders of magnitude difference between quiet times and peak activity.
From a practical point of view, when viewed from the the first Lagrange point L1, solar radio bursts can be much higher in intensity than any artificial radio source observed from Earth, e.g., see links for the Wind WAVES radio data from https://wind.nasa.gov. Or type "solar radio burst" and look under Images to see numerous examples. The artificial sources will show up as horizontal, narrow bands in the images of frequency versus time spectrograms. Note that Wind has had a rather large diversity in orbital configurations, as discussed in Wilson et al. 
- Cecconi, B., et al., "NOIRE Study Report: Towards a Low Frequency Radio Interferometer in Space," arXiv 1710.10245, 2017. (Refereed version found at: 10.1109/AERO.2018.8396742)
- Wilson, L.B., et al., "A Quarter Century of Wind Spacecraft Discoveries," Reviews of Geophysics 59(2), pp. e2020RG000714, doi:10.1029/2020RG000714, 2021.