I agree with BigA. This is an overseas scam that has been reported in the news. In fact my mother and childhood friend received these calls. They are looking to target the elderly and other vulnerable people. Do not allow yourself to become their next target. Ignore the calls and block the number if you can.
I received a call stating I had won 2.5 million dollars from the New York lottery commission. They had the nerve to leave me a voice message. I don't answer calls I don't recognize the number. Here's the number that called me (347) 985-8039.