Investing in stocks can make you money in two primary ways. The most important way is for share prices to rise. Many stocks also deliver additional returns by paying dividends.

Every investor loves to see the prices of stocks they own go up. But don't discount the power of dividends to generate impressive gains over the long term. Here are three stocks that could double your money in 10 years on dividends alone.

1. Devon Energy

The "rule of 72" is a simple way of determining how long it takes for a given investment to double. Divide 72 by the expected rate of return and you'll get the approximate amount of time before the investment will double. 

Devon Energy (DVN 0.77%) currently offers a dividend yield of nearly 9.1%. Using the rule of 72 shows that the stock could double your money in a little under eight years on dividends alone at the current yield. But investors haven't needed to depend on just dividends with Devon. Shares of the oil and gas producer have soared close to 35% year to date. 

However, Devon's momentum relies largely on crude oil prices. So does its dividend, to some extent. The company's dividend consists of a fixed component and a variable component based on excess free cash flow. Because crude oil prices have declined in recent months, Devon's free cash flow fell. As a result, the company reduced its variable dividend payout.

The potential volatility of its dividend could mean that Devon's dividends won't be able to double your money within the next 10 years. However, some projections of oil prices over the rest of the decade bode well for Devon's prospects of generating strong free cash flow. If crude oil prices don't slump too much, Devon should be a doubler.

2. Medical Properties Trust

Unlike Devon, Medical Properties Trust (MPW 0.10%) (MPT) doesn't have a variable component of its dividend. The healthcare real estate investment trust (REIT) has steadily increased its dividend for eight consecutive years. 

MPT's dividend yield currently tops 9.8%. That's enough to double your money on dividends alone within a little under 7.5 years.

The problem for MPT this year is that its share price has plunged so much that it wiped out years of dividend payments. The stock has performed so dismally because of concerns about the financial positions of its hospital operator tenants. 

But I view MPT as one of the top stocks to buy right now. One reason why is that the steep sell-off has made the REIT's valuation really attractive. Another is that the outlook appears to be improving for hospital operators thanks to increased reimbursements. MPT's dividend appears to be in good shape. If the yield declines, it will most likely be because the stock has gone up. 

3. Verizon Communications

Verizon Communications(VZ 2.26%) dividend is currently just a hair under 7%. That's not quite enough to double your money on dividends alone in 10 years. However, I still think that Verizon deserves a spot on the list for one simple reason: its track record of dividend increases.

The telecommunications giant has increased its dividend for 16 consecutive years. Even a few small dividend hikes over the coming years would be enough for Verizon's dividends to double your money by the end of 2032.

There are two key questions, though, with Verizon. First, is its dividend safe? Second, could the stock's performance cancel out any dividend gains (as has been the case this year)?

I think the answer to the first question is an easy one. Verizon's dividend appears to be quite safe. The company's dividend payout ratio is under 56% -- a respectable level. Verizon's management knows that investors are attracted by its dividend. I suspect they'll do everything they can to keep the streak of dividend increases going.

As for Verizon's future stock performance, that's more difficult to predict. But the telecom company's shares trade at less than 7.4 times earnings. I don't think the stock will decline significantly below its current level with this already attractive valuation.

Verizon also has growth opportunities with the adoption of its 5G services. The bottom line is that there's a good chance that Verizon's dividends could double your money over the next 10 years without its stock performance negating those gains.