This number keeps texting me saying I won a lottery

For a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number.

For text messages: forwarding any text message spam you get to the short code  “7726,” which spells “spam” on most phones, to alert your network operator to the abuse. ATT won't accept 7726 But they will accept BLOCK and return a message that the web site is blocked. forward the texts to 7726 or BLOCK, depending on your phone carrier.
http://www.att.com/esupport/article.jsp?sid=KB115812

Report your callers here, not just to the DNC alone:

https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
https://complaints.donotcall.gov/complaint/complaintcheck.aspx?panel=2

By State DNC lists:
http://800notes.com/res/DoNotCall.aspx

Prize Offers: You Don’t Have to Pay to Play!
http://www.ftc.gov/bcp/edu/pubs/consumer/telemarketing/tel17.shtm
http://www.consumer.ftc.gov/scam-alerts
http://www.consumer.ftc.gov/articles/0076-telemarketing-scams
http://www.usa.gov/
*********
http://www.consumer.ftc.gov/articles/0119-jam ... ng-us-consumers

Got a text from this number last night that said "You are the winners of June lottery cash promotion for the One Million Two Hundred Thousand US Dollars.  We will work assiduously to realise this mandate as we respect your views, most importantly protect your privacy. For more information kindly email:"
They didn't leave an email and obviously don't speak English very well.  Definitely a SCAM.