What is the highest chart topping song written by Nanker Phelge?

That's a name the Rolling Stones used early in their career for B-sides, instrumentals, unofficial releases. Their other songs gave royalties to Mick and Keith but the Nanker Phelge were assigned to the whole band. Some of those songs were later just accredited to RIchards/Jagger like "2020 South Michigan Avenue".

The biggest chart hit on Billboard was "Play With Fire" as it was the B-side to "The Last Time", which hit number one in England. "Play With Fire" hit number #96 in the US Hot 100 for Billboard.