If you're going to invest in dividend stocks, you want to make it worth your while. The typical S&P 500 stock yields just 1.6%, but there are many other investments out there that yield a whole lot more. But it's important to be careful and not overly aggressive when choosing dividend stocks, as high yields may not last, especially when the economy is not faring so well.

But three stocks that pay you more than 4% today and are safe long-term buys are GlaxoSmithKline (GSK -1.58%)Telus (TU -0.61%), and Southern Company (SO 0.45%). They're profitable companies with strong business models that won't put their payouts at risk. Here's a closer look at why they're worth investing in right now.

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Image source: Getty Images.

1. GlaxoSmithKline

Drug manufacturer GlaxoSmithKline currently pays investors a top yield of 5.8%, and its payout ratio of 70% looks very manageable. However, with GSK planning to split its business into two -- one will be focused on consumer health and the other on developing drugs -- that picture will change. GlaxoSmithKline has indicated that its aggregate distributions will likely come down from where they are today, but it's unclear how the different dividend rates for the two businesses will look. Given its relatively high payments, there's still plenty of room for a reduction in the dividend and for investors to earn a great yield. The change won't happen until 2022, giving investors time to decide which business to invest in, or whether to hold positions in both companies.

The company is coming off a good year in 2020, as it demonstrated stability during a year full of challenges for the industry. On Feb. 3, GlaxoSmithKline reported its year-end results for 2020, in which revenue totaled GBP$34.1 billion and grew by just over 1%. Although its pharmaceutical and vaccine sales dropped from where they were a year ago, the company's consumer health segment showed strength, growing at a rate of 12%. GlaxoSmithKline's overall profit of GBP$6.4 billion also rose by 21.3%.

These numbers might suggest that consumer health is the more appealing business to invest in once the company splits into two. However, GSK said that it has more than 20 products in its biopharma pipeline that it could launch by 2026, and over 10 of them could generate more than $1 billion in peak annual revenue. Staying invested in both businesses can be a good way for income investors to get a good mix of both dividends and growth. And now could be a great time to buy it on the dip, as shares of GlaxoSmithKline are down 20% over the past 12 months, while the S&P 500 has risen by 16%.

2. Telus

If you're strictly after dividend income and just want to collect a recurring payment, Telus is a stock you'll like. With limited volatility and a yield of 4.6%, this telecom provider makes for an easy buy-and-forget investment you can tuck away in your portfolio for years. Its current payout ratio also sits at 70%, and the stock can be a great alternative to putting money into a low-interest-paying bank account, as it is up a modest 5% over the past year.

As for the business, it's also doing well even amid the pandemic. Although COVID-19 has negatively affected the company's bottom line with fewer people roaming and its retail stores having to shut down, on Nov. 6, 2020, Telus still reported a profit of 989 million Canadian dollars over the nine-month period ending Sept. 30, 2020. Although it was down 44.3% year over year, the company still generated year-over-year revenue growth of 5.6% during the period as its wirelines business grew by 16.2%, more than offsetting losses in its wireless segment, which fell by 3.1%.

Despite the drop in profitability, Telus still looks to be in good shape. Things will get a whole lot better for business once people are traveling again, which could happen soon now that the COVID-19 vaccine rollout is under way.

3. Southern

Utility companies also make for great income investments, as they're incredibly stable and offer products that are not wants, but needs. Although Southern's 4.2% yield is the lowest on this list, it makes up for that with rock-solid financials. Over the past three quarters, the company has generated $15.3 billion in revenue, which is down 7.6% year over year. Southern blames the declining sales on COVID-19 and on milder weather during the year. But with profits of $2.7 billion during that time, the company still had a strong net margin of 18%. The company serves more than nine million customers across six states, providing them with electricity and natural gas. Through its subsidiaries, it also offers telecommunication services and is a fiber optics wholesaler.

The most noticeable effect of the pandemic was evident in the commercial segment, as more people worked from home and some businesses closed, which led to a decrease in the demand for electricity in office spaces. Commercial kilowatt-hour sales declined 8.4% over the past nine months, followed by a 7.8% drop in the industrial segment. In the residential market, however, sales were down a more modest 3.5% -- which was due to milder weather. 

Southern's payout ratio is a bit high at over 80%. It's a risk because if things don't improve, the company could be tempted to reduce its payouts to give itself a little more breathing room. The $2.7 billion in profit it reported over the past nine months was 36.4% lower than it was in the previous year. But as things normalize in the economy and businesses get back to operating normally, profits should improve. And that's already starting to happen -- in the third quarter ending Sept. 30, 2020, Southern's bottom line totaled $1.3 billion and was down just 4.9% from the prior-year period. Although it may be an uncertain road ahead, Southern's dividend payments still look to be safe. In the past 12 months, Southern's shares have fallen 11%, making now a great time to lock in its above-average yield.