Comparison of the mean number of companions per dwarf between the Apertif and the SDSS samples. Left: case with no constraint on the projected radius between companions in Apertif. The blue line represents the result for the total drawn galaxy sample; the dotted pink represents the results from the isolated drawn sample by taking the lower limit (see Sect. 5.1); and the dashed orange line represents results from B18. Shaded regions represent 1σ errors. Right: same as in the left panel, but excluding all companions in Apertif for which r_p < 55″.