You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Apollo

Context:
Some common epithets of Apollo as a healer are "paion" (παιών, literally "healer" or "helper") "epikourios" (ἐπικουρώ, "help"), "oulios" (οὐλή, "healed wound", also a "scar" ) and "loimios" (λοιμός, "plague"). In classical times, his strong function in popular religion was to keep away evil, and was therefore called "apotropaios" (ἀποτρέπω, "divert", "deter", "avert") and "alexikakos" (from v. ἀλέξω + n. κακόν, "defend from evil"). In later writers, the word, usually spelled "Paean", becomes a mere epithet of Apollo in his capacity as a god of healing.

Question:
In classical times, what was Apollo's strong function in popular religion?

keep away evil,