Google's hardware support number for all Nexus products in the United States is (855) 836-3987. As of 2015, it can be called 24-hours a day, seven days a week.
Google also offers several other support services for all of their products. In order to access these services, all users must be logged into their Google accounts. After logging in, individuals who need assistance can visit the Google Play support website and click on the "Contact Us" link at the top-right portion of the page. Doing so brings up a list of customer support options, including the ability to chat with a support representative.