Does anyone recognise this number?  It keeps coming up on my phone bill - only 0.06 seconds at the same time (usually 11.34 or thereabouts) but charges £0.17 each time.  Not a lot I know but annoying.  I tried dialing it with 141 before but just goes dead.

Sounds like a Burglar Alarm / Security System calling out as suggested.

The other possibility is if you have Sky its your Sky Box calling out but it shouldnt be doing it that often.