One of the best ways to maximize your odds of earning a great return on a stock is to buy it when it's dirt cheap. But with the average stock on the S&P 500 now trading at more than 27 times its earnings and the index soaring 15% over the past 12 months, it's not easy for investors to find great deals.

The good news is there are still some incredible bargains out there. Three ridiculously cheap stocks that you should consider buying right now are AbbVie (ABBV -1.03%)Lumen Technologies (LUMN -5.15%), and Dell (DELL -0.36%). They're trading at relatively low multiples to earnings and 2021 could be a good year for their businesses.

An arrow showing a rising stock price.

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1. AbbVie

AbbVie is a top healthcare stock that got a whole lot bigger in 2019 after closing on its $63 billion deal to acquire Botox-maker Allergan. Although the immunosuppressant Humira remains the company's top-selling drug, AbbVie will lose patent protection on it in 2023. So it makes sense that the company is looking for avenues to diversify as it tries to prepare for the inevitable decline in revenue. But with a broad portfolio that includes drugs in various categories, including immunology, aesthetics, eye care, and women's health, AbbVie has many opportunities for growth down the road.

Through the nine-month period ending Sept. 30, AbbVie's total revenue of $31.9 billion was up 30% from the prior-year period -- largely due to the inclusion of Allergan's results, as the deal didn't close until May of last year. However, its earnings of $4.6 billion during the period were down 9.9% year over year. 

But those numbers will get better as Allergan and AbbVie continue to integrate and eliminate redundancies to make their operations more efficient. Today, AbbVie stock trades at a trailing price-to-earnings (P/E) ratio of 23, which is still cheaper than the average stock on the S&P 500. However, when you look at its forward P/E, which takes into account the earnings analysts are expecting from the company in the future, that multiple comes down to just nine.

Despite climbing 18% over the past year, AbbVie still looks like a bargain buy, especially as hospitals hope to resume more of their day-to-day operations this year and physicians are likely to prescribe more drugs to the many patients who skipped doctor visits during the pandemic. And with a dividend yield of about 5% (well above the S&P 500 average of about 1.6%), there's even more of an incentive to load up on the stock right now.

2. Lumen 

Lumen, previously known as CenturyLink, is another cheap stock that might be too good of a buy to pass up on. The company's shares are down 22% over the past 12 months and could be due for a rally. Its trailing P/E is 8, and with an even lower forward P/E of 7, the stock looks like a bargain.

The Louisiana-based company is well-positioned to meet the needs of businesses that are trying to be more digital and remote. Through its Hyper Wide Area Network, Lumen helps offices get online, and its VPN ensures those connections are safe and private.

Over the past three quarters, the company's revenue of $15.6 billion has fallen 3.5%, but without goodwill impairment charges (which totaled $6.5 billion a year ago) weighing down its operations, it's produced a profit of $1.1 billion compared to a loss of $5.5 billion in the prior-year period.

With the rollout of multiple vaccines likely slowing down the pandemic this year, 2021 should be a better year for the economy. And that will lead to stronger demand for Lumen's services, making a recovery in the stock's price a real possibility this year. Its cheap price will only make it more attractive to value investors. It also pays an attractive quarterly dividend of $0.25, which at a share price of $10 yields 10% per year, and that could make it a hot buy for income investors.

3. Dell

Like Lumen, Dell is a business that will thrive as companies invest more into the cloud and technology in general. And although it is the best-performing stock on this list, rising 44% in value over the past year, it still may not be too late to buy shares of Dell. Its trailing P/E ratio is 23, which isn't all that cheap -- at least not until you look at its forward P/E, which is drastically lower at a multiple of just 10.

What makes Dell an appealing investment is that the tech company's business has been fairly stable, even amid the pandemic. Sales over the nine-month period ending Oct. 30 totaled $68.1 billion, which was flat from the prior-year period. And with less spend on selling, general, and administrative expenses, its operating income of $3 billion was a 55.7% improvement year over year.

Dell's diverse mix of physical computer products along with cloud-based solutions makes it a safe and diverse buy. In what should be a stronger economy this year, Dell could perform even better as companies upgrade their existing hardware and make the most of the cloud to support remote workers -- a trend that could be here to stay. It's the only stock on this list that doesn't pay a dividend, but that doesn't make it any worse of a buy, as Dell could have a fantastic year in 2021.