It's a number provided by the TextPlus service, very popular with the craigslist and dating site scammers. If they're doing something against the law you should:
Contact law enforcement, the FTC, etc. (depending on what they have done)
Let TextPlus know: abuse (at) textplus (dot) com
Let people here know the details so they can avoid becoming victims.
Block them
I received an email from someone giving me this number to text him. The email is from a stranger saying they want to date me, etc. Smells scammy to me!
I work for a company called Precision Civil Engineering. On 10/19/2016 a person going by the name of Kenneth Elliott committed identity theft and used my company's information to create their own email server and began sending emails impersonating employees of my company. Our investigation has shown that this is a scam that is likely originating from a server in Russia. Official complaints have gone out to the company that hosts the server, as well as the company that set up the domain and to TextPlus. Also, the FBI were notified and they are investigating the issue.
I apologize to anyone who has been bothered by this person, but my company is doing everything we can to shut this person down.