Numbers with this prefix were first introduced in 1997.While 5103043196 was originally issued with the info above, the owner of the phone number (510) 304-3196 may have transferred it through a process called porting.
Caller name: textmessage
Caller type: Text/SMS
It said: "We've picked you for a 1000 DOLLAR VOUCHER right now. It's entirely FREE. Please go to www.rewards-voucher.com (WALMART 023455 #ESC# to remove)"
Seriously an obvious fake.