I am having the same issue as reported above. Daily I get a call from this number and when answered they hang up. When returning the call they do not take direct calls to the extension.
I think this number is in a series of hundreds of numbers in the same exchange being used as "redirect calls" by individuals who DO NOT want to be traced.
These numbers are sold to individuals and businesses it appears.
Particularly to cheating husbands and wives who DO NOT want their calls traced back to them.