Who called from 2402521325

I am getting these calls daily.  Sometimes a female caller who asks for me by name.  Mostly they just hang up when I answer.

They are most likely  trying to get your name and record your voice so they can attempt identity theft. Be careful.

Many calls from this number in the last week or so.  "Unavailable caller".  As of now, I'm blocking this #.  I do not answer "Unavailable" calls.

Called my work number today, and hung up when I answered.

Called my cell number today, 15 April 2013.  
I do not give this number out except for a few colleagues.  
I did not answer and there was no message.