It is a scam. Apple doesn't make unsolicited phone calls. If there was a problem you would be notified when attempting to log in, including when logging into this forum. Also see: Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support
Also, the caller id number shown on scam and marketing calls is frequently not the number actually originating the call. The number is often spoofed.
One option to consider is Settings > Phone > Silence Unknown Callers. See: Detect and block spam phone calls - Apple Support