800-000-0888 called cell, no message

this number called my cell phone twice today.
the 1st time i forwarded to voicemail- no message left
then it called back about 2 minutes later. I answered & I heard nothing & it hung up before i did. Weird

Showed this number on caller ID. Never saw one come up 800-000/prefix. Didn't answer, hung up when machine answered.