There are many such services , a google search will give you hundreds of results but I would suggest that you try Swytch for WhatsApp. I have used Swytch and it gives you a free trial so you can test and check it out before you buy one.
But be careful while using virtual numbers of sites which are not trust worthy as you can lose a number and you wont have any control over it.Swytch gives you a complete control and also allow you to use that number for sms and calls.
