0873281997

This is the main number used for Telemarketing and Customer Surveys by OPTUS.
Nothing to worry about, just ignore it or tell them you're not interested and eventually they'll stop calling.

always got miss call from this number from last week,never answer

just got a missed call from this number, thanks :)

Currently in Europe for a 5-week holiday and yes, do have the mobile on roaming but turned off mobile data and have not even used it for calls or msgs for a month now. I only got roaming in case of emergencies.
This number has been calling me for the past 3 weekdays around 10am-12 noon in Oz, but I'm in EU at the moment and we are 8 hrs behind, it is in the middle of the night! I'm so glad I found this page, I feel better that I can ignore them as I've instructed no calls from Oz unless it's an emergency.
After 2 unanswered calls, take the hint Optus. Plus your database has me on roaming... I'm overseas at the moment!

I got 5 or six calls from this number over a two day period.  When I answered, it hung up.
I rang it back and got an automated message that it was Optus (who I have been a loyal customer to for a decade or more).  I rang there service number 133937 and eventually got put through to the right department.  
The lady that then dealt with my complaint couldn't have been more helpful (even though I was maybe a little less civil than I like to be).
Her promise was to remove my number from the telemarketing list (which apparently generates these calls).  It would appear that the numbers are dialled automatically and then forwarded to the next available telemarketer.  If all the telemarketers are already busy when you answer, then your call will be dropped.

I got a call from this number but did not answer, googled the number and came here. simply blocked them from calling =) (iphone5 can block callers).

This number is optus.