A toll-free number that spells something and is therefore easy to remember is sometimes called a "vanity number." This turns your 1-800 number into not only an investment in customer relations, but also a marketing investment. Customers are more likely to remember your name and are more likely to call you if your phone number is clever, spells your company's name, or uses a memorable combination of numbers such as 1-800-555-5555.
However, it is probably not worth getting a vanity number unless it truly does have the potential to increase customers' memory of both the number and your company's name. A dog grooming company will probably not profit by choosing the number 1-800-382-9PUP. The word "pup" won't help customers to remember that it is a dog grooming company as opposed to something else to do with dogs. And the 3829 combination means that for most people, they are still going to need to write this number down.
If there is any possible global component to your company's business, you have several additional considerations you need to keep in mind. (And remember that the capabilities of the internet means that almost every company has some potential for outreach to global audiences.)
In this situation, first, make sure that the words spelled out by a vanity number don't mean anything crude or ridiculous in another language. You can find this out fairly easily on the internet by searching for the words included in your potential vanity number.
Second, you will want to include the actual numbers on your web site or other internationally distributed information, along with the word or phrase that the phone number spells. This is important because phones in other countries are often made without letters on the number keys.