Massive telecom company AT&T (NYSE:T) isn't regarded by many investors as an exciting stock, and for good reason. The backbone of AT&T's revenue is utility-like mobile-phone payments, and several other areas of the business have generated underwhelming results recently.

However, this could be the kind of stock that could make you rich over the long run. Here's why AT&T could have more growth potential than you think, and why its dividend is not only safe but is likely to continue growing for the foreseeable future.

A group of seated people with coffee cups and mobile phones

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AT&T could have lots of room to grow

To be fair, AT&T's recent growth hasn't been too impressive. Excluding the addition of the recently closed Time Warner acquisition, the company's revenue was roughly flat in the third quarter.

Notably, AT&T's entertainment revenue is declining, as is revenue from the company's business wireline services. Just to name one troubling statistic, the company's DIRECTV satellite business lost 359,000 subscribers in the last quarter alone (although the DIRECTV NOW service added 49,000). Currency headwinds have been a drag on the company's Latin America business. And AT&T is saddled with quite a bit of debt after its acquisition spree over the past few years, which understandably makes some investors nervous.

However, there are some pretty big catalysts that could fuel growth. Warner Media gives the company an edge over competitors when it comes to content, and creates interesting possibilities to incentivize customers to use AT&T's other offerings. In fact, the company recently said that the acquisition was immediately earnings-accretive, responsible for $0.05 of AT&T's $0.90 in earnings per share during the third quarter.

5G wireless technology is another big one. AT&T gets about four-fifths of its revenue from telecom services, and the upcoming rollout of 5G service could be a big tailwind, especially if AT&T achieves a wide-scale rollout quicker than its peers. John Donovan, chief executive of the company's communications division, recently told the Wall Street Journal that he expects to see 5G-capable handsets and other devices hit the market in large volume in late 2019.

AT&T's phone business has been a strong point in recent quarters, and the rollout of 5G could bring even more customers into the company's ecosystem. I wouldn't expect to see a meaningful impact from 5G right away, but in 2020 and beyond, it could be a nice generator of growth for the company's most important revenue stream.

A high, sustainable, growing dividend

Even without the growth potential, AT&T produces a pretty nice return just based on its dividend. As of this writing, the stock pays $2.00 per year, which translates to a dividend yield of about 6.7% based on the current price.

While this is certainly a high dividend, AT&T expects to earn about $3.50 per share for 2018, so the payout is well-covered. Analysts expect earnings to grow by about 2% to $3.58 in 2019, so there's no reason to believe the company's impressive 34-year streak of dividend increases is in jeopardy, especially considering the tailwinds that could boost earnings beyond next year.

It's also worth noting that next year's projection gives AT&T a forward price-to-earnings ratio of about 8.4 -- a dirt cheap valuation that essentially prices in zero growth.

This combination can help you get rich over time

To be clear, I don't expect AT&T to achieve massive growth over time, but it doesn't need to in order to produce market-beating returns. After all, if the company grows revenue (and its stock price) by an average of just 4% per year, combined with a 6% dividend yield, it can produce 10% annualized total returns for investors. And I think 4% annual growth is a conservative projection.

The stock won't make you rich overnight, but the combination of steady, modest growth and strong dividends can have amazing results over time. If your goal is to retire as a millionaire, AT&T could be a smart addition to an investment portfolio that can get you there.

Matthew Frankel, CFP owns shares of AT&T. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.