Even Google Telecom and Optus have no record of this number. It LOOKS like a mobile number but its most likely (imho) to be a V.O.I.P. generated number from a scammer. If you ring them back, ( on others of these types of calls I got ), you find they dont get or receive calls from an outside line, ( you, your phone etc.) That they are busy, no contact is available or it rings & (IMHO) they record your number ringing in so they can sell it off to others to make contact with you.