Complex sentence: With a frenetic activity level in the 1970s and 1980s, he remains one of the artists with the most number 1 hits, totaling 52, his number of top 40 list-songs being 18.
Split into simpler sentences: With a frenetic activity level in the 1970s and 1980s, he remains one of the artists with the most number 1 hits (totaling 52). His number of top 40 list-songs being 18.