This number is a definite scam caller.
I answered the phone early in the morning (Western Australian time) and heard a pre-recorded voice saying "This is final reminder from Australian Tax Office..."

Don't know what else it said after that because I hung-up on the scamming bastard.
I missed an even earlier morning call a few days prior that was number (02) 6413 9320 - very similar to this number so it's possible it's also part of that scammer network