Dividend investing is a tried-and-true strategy for generating strong, steady returns in economies both good and bad. But as corporate America's slew of dividend cuts and suspensions over the past few years has demonstrated, it's not enough simply to buy a high yield. You also need to make sure those payouts are sustainable.

Let's examine how ExxonMobil (NYSE: XOM) stacks up. In this series, we consider four critical factors investors should examine in every dividend stock. We'll then tie it all together to look at whether ExxonMobil is a dividend dynamo or a disaster in the making.

1. Yield
First and foremost, dividend investors like a large forward yield. But if a yield gets too high, it may reflect investors' doubts about the payout's sustainability. If investors had confidence in the stock, they'd be buying it, driving up the share price and shrinking the yield.

ExxonMobil yields 2.2%, a bit higher than the S&P 500's 2%.

2. Payout ratio
The payout ratio might be the most important metric for judging dividend sustainability. It compares the amount of money a company paid out in dividends last year to the earnings it generated. A ratio that's too high -- say, greater than 80% of earnings -- indicates that the company may be stretching to make payouts it can't afford, even when its dividend yield doesn't seem particularly high.

ExxonMobil has a payout ratio of 22%. That may seem conservative -- and it is -- but exploration and production companies often have low payout ratios to conserve cash flow for capital projects. Also keep in mind that ExxonMobil uses quite a bit of its cash to buy back stock -- last year, it spent more than twice as much on buybacks as it did on dividends.

3. Balance sheet
The best dividend payers have the financial fortitude to fund growth and respond to whatever the economy and competitors throw at them. The interest coverage ratio indicates whether a company is having trouble meeting its interest payments -- any ratio less than 5 is a warning sign. Meanwhile, the debt-to-equity ratio is a good measure of a company's total debt burden.

ExxonMobil has a debt-to-equity ratio of just 11% and an interest coverage of 219 times.

4. Growth
A large dividend is nice; a large growing dividend is even better. To support a growing dividend, we also want to see earnings growth.

Over the past five years, ExxonMobil's earnings per share have grown at an average annual rate of 5%, while its dividend has grown at a 13% rate. That earnings growth beats out competitors such as ConocoPhillips and BP, though it lags Chevron's 11% rate.

The Foolish bottom line
So is ExxonMobil a dividend dynamo? Perhaps. Its yield is only moderately high, but the oil giant exhibits a safe dividend bill of health. It has a modest payout ratio, a tiny debt burden, and growth to boot. If you're looking for some other great dividend stocks, I suggest you check out "Secure Your Future With 11 Rock-Solid Dividend Stocks," a special report from The Motley Fool about some serious dividend dynamos. I invite you to grab a free copy to discover everything you need to know about these 11 generous dividend payers.