Got a call from that number at 2am! Also I have beeen geting calls since 5 am from a number in the UK and it is Christmas Eve! I wonder if they are related? The UK number has called me 9 times in the past 5 hours!
I signed up for a Gmail account today - it gave me the option of a SMS or a phone call to verify the account before i could proceed ... 6503539140 was the number calling
The phone calls also occur when Google is confirming a password change request. For example, if someone were attempting to reset the password for your GMail account, then google sends the authorization code to you. They do not change the password until you enter the code. In this way they assure the request is authorized by you.
Multiple calls from this number at 4am. I can't understand the language (Mandarin? Cantonese?) but it does seem to be reciting a verification code. I didn't request any new accounts or password changes, although I'm changing my passwords now!