If you want an investment to make you a millionaire, you need three things. The first is some decent money to invest in the stock market, ideally at least $20,000. The second is time and patience -- big returns don't come quickly unless you're taking on significant risks. The third is an above-average return, which comes from owning a solid growth stock that can beat the market over the long haul.

Could AbbVie (ABBV -4.58%) be that stock for you? It is one of the largest healthcare companies in the world, and its revenue has grown by more than $20 billion since 2019. Can this growth-oriented business help you achieve market-beating returns and get your portfolio to more than $1 million?

You can buy the stock at a discount

Investors are discounting AbbVie's stock today, and that can be a huge advantage for growth investors looking for a stock to hold on to for the long haul as it could help secure big returns later on. AbbVie shares are only trading at 12 times its estimated future earnings, which is a big discount to the 19 times forward price-to-earnings multiple that the Health Care Select Sector SPDR Fund averages right now.

AbbVie is facing some challenges ahead, particularly as its top-selling drug Humira generates less revenue due to rising competition. But there's no shortage of reasons to be optimistic about the company's long-term future.

Plenty of growth on the horizon

What's appealing about AbbVie's business is that although it's in the midst of a transition, with immunology drugs Skyrizi and Rinvoq replacing Humira and eventually making up for its decline in revenue, it does have other catalysts out there.

Its pipeline, for instance, has more than 50 programs that are either in middle or late stages of development. Not all of them will be successful, but AbbVie may be able to generate a handful of big wins. If so, they can collectively add to the company's top and bottom lines, and provide the business good opportunities for growth.

AbbVie already has some promising blockbuster drugs on the way. Besides Skyrizi and Rinvoq, which are the company's rising stars, it has other assets it can rely on for sales. Schizophrenia medication Vraylar may be able to bring in up to $4 billion in annual revenue at its peak, according to analysts. Another promising product is migraine treatment Ubrelvy, which estimates suggest can bring in at least $1 billion at its peak.

Strong financials allow more opportunities

If you're investing for the long haul, you also need to know whether the business's financials are strong. Patents expire, and a pharmaceutical company will always need money to invest in research and development to help set it up for future revenue. While AbbVie does have some great assets, to truly be a stock with millionaire-making potential, it would need to offer even more.

What's promising about AbbVie is that its operations are highly profitable. Over the trailing 12 months, the company has reported an operating profit of $15.8 billion on revenue of $55.1 billion, for an operating margin of 29%.

An even more important metric for growth investors is free cash flow (FCF) -- the cash flow the company has left over after paying for its capital expenditures. In essence, this is what's available to either distribute to shareholders or invest back into the business. In the past four quarters, AbbVie's FCF has totaled $24.7 billion. That's a healthy amount of free cash.

But one caveat: AbbVie also pays a dividend (it currently yields 4.5%), and over the past year it has spent $10.4 billion on those payouts. The company still has a good chunk of free cash flow after paying dividends, but it's important to remember that all that cash isn't simply available for growth initiatives.

Overall, however, AbbVie is well-funded and is generating strong enough cash flow that it can both spend and invest in promising opportunities.

Can AbbVie's stock make you a millionaire?

If you're asking if AbbVie can make you a millionaire, you may be asking whether the stock can grow to more than 30 times its current share price. That's because most investors probably can't afford to invest more than $30,000 into a single stock. You'd actually need better than a 30-fold return for $30,000 to turn into $1 million; your investment would need to grow to over 33 times its current value. And the less money you invest, the greater the return will need to be.

Rounding down and assuming you need a 30x return or greater, that means AbbVie would eventually need to be worth more than $7.3 trillion. That's what its market capitalization would be if it grew to more than 30 times what it is today. It's a huge return, but if it rose at a rate of 12% for a period of 30 years, it would reach that valuation.

It's not an easy task, and could be a long shot (though the S&P 500 has averaged a return of more than 10% in the long run). But even if it's unsuccessful, AbbVie can still make for a solid growth stock to buy and hold for the long haul.