Lagos, Nigeria (CNN) On first look, not much separates the two front-runners contesting Nigeria's presidential election. Both are men in their 70s with previous experience of high-level politics. Both are from the same ethnic group. And both are Muslims from the north of the country.

Incumbent President Muhammadu Buhari, of the All Progressives Congress party, known as the APC, and Atiku Abubakar, of the People's Democratic Party, or PDP, will face the Nigerian electorate on February 16 when Africa's largest democracy votes.

Although they share demographic similarities, ideologically, the two men are opposed.

Buhari, who took power in a military coup in 1983 and was ousted in another coup before waiting almost three decades to be eventually elected president, relies more on the government and public sector and is suspicious of investment, both domestic and foreign, says financial analyst Bismarck Rewane

Abubakar, who served as vice president from 1999 to 2007, is a staunch capitalist who made his fortune investing in various sectors in the country.

Regardless of who the electorate picks -- and there are 70 more candidates to choose from -- the outcome will dramatically shape the fortunes of Nigeria's more than 190 million people.

The vote comes at a critical time for the country's economy, a lynchpin of the region. The recent oil price crash sent Nigeria's economy into turmoil when the price of a barrel plunged to $40 at its lowest from a high of $100, leaving the country's major revenue source depleted.

Although the country has emerged from recession and GDP grew slightly, 87 million Nigerians now live in poverty, the highest number of impoverished people in the world, overtaking India to move into the top spot in 2018, according to The Brookings Institution

Last year, philanthropist and billionaire Bill Gates bluntly told Nigeria's politicians they needed to abandon infrastructure projects and focus on developing human capital and the country's large youth population, which at more than 60% of the population , is one of the highest in the world.

"The current quality and quantity of investment in this young generation in health and education just isn't good enough," Gates told CNN

Supporters of Buhari's key opponent, Abubakar, say his election will be vital in reviving Nigeria's economic fortunes because of his strong business acumen.

"Nigeria is a Fortune 500 company, and Atiku is the man to lead it," says Ben Murray-Bruce, a businessman and PDP senator.

"He wants to grow a trillion-dollar economy and create jobs. He has made and lost billions and knows how to do this."

Abubakar, a multimillionaire entrepreneur, has interests in many sectors including agriculture, real estate, and a microfinance bank, which he said gives 80% of its loans to women.

He also owns the American University in Yola, where some of the freed kidnapped Chibok girls -- taken by Boko Haram -- attend on government scholarships.

Abubakar, who has three wives and 28 children, describes himself as a supporter of gender equality.

Born to a firewood seller in Yola, Adamawa State in northeast Nigeria, he was an only child who grew up very poor and lost his father early in life. This journey has driven him to create wealth and have compassion for the poor, according to Murray-Bruce, who cites Abubakar's philanthropic works in the country.

Abubakar has been trying to become president since he was vice president and has campaigned four times.

Now 72, this is perhaps Abubakar's last chance at the top job. But his candidacy has been dogged by persistent allegations of corruption, which stem from his time in office.

Abubakar has faced claims that he used his time in office to enrich himself and his friends.

Former President Olusegun Obasanjo, who he served under, was one of his most vocal critics, but the pair have since reconciled, with Obasanjo recently endorsing him for the presidency.

Abubakar dismisses the claims of corruption, stating that he has never been charged or indicted.

"They are all allegations. I have dared people publicly that if anybody has any evidence of corruption against me, let him come out. I've never been found wanting. But people will always accuse you," he said.

"But you cannot stop being accused of corruption as long as you're a politician in a developing country."

Abubakar said the biggest impediment to him becoming president will be election fraud.

The international community, including the United Kingdom and the United States , recently expressed concerns over free and fair elections in Nigeria when President Buhari abruptly suspended the country's chief justice, Walter Onnoghen, who is facing corruption charges after accusations he did not disclose his assets, including several foreign bank accounts.

Abubakar's camp viewed the move as politically motivated and unconstitutiona l.

Buhari has dismissed concerns and his government issued statements warning against foreign interference in the elections.

Consequently, Abubakar suspended his campaign for 72 hours as a "symbolic protest." "I am particularly worried about the conduct of the next elections," he said.

Just four years older than his main opponent, Buhari, like Abubakar, had tried many times to take the top job.

Now bidding for a second term, the septuagenarian's health has been much scrutinized.

From May 2016 until mid-2017, Buhari visited the UK for medical treatment; it prompted fake news reports that he had died in London and in a strange recent episode he was forced to deny claims by some Nigerians that he died and was replaced by a clone.

Buhari did not respond to requests for an interview for this story.

However, one of his closest aides, Abike Dabiri, said Buhari is fit to lead the country after his "miraculous recovery."

"He is now healed. He had a debilitating illness and had to go through blood transfusions but he has come back stronger and healthier."

According to Dabiri, Buhari's reputation for integrity means he can be trusted.

"You can be sure that President Buhari will not take your money. That is why the African Union declared him the anti-corruption tzar for Africa," she said.

Although he claims to have a zero tolerance reputation in his fight against corruption, Transparency International said Nigeria has "neither improved nor progressed in the perception of corruption in the public administration in 2018," in its latest Corruptions Perception Index

Buhari swept to power on a promise to tackle the scourge of Boko Haram. However, the jihadi group appears strengthened and one faction has forged stronger links with ISIS to create the Islamic State of West Africa Province, and the group is staging attacks on military bases and displacing thousands of Nigerians

This faction also executed two International Red Cross aid workers last year.

Dabiri defended Buhari's record on the militant group, saying he has done more than previous administrations to contain the Boko Haram threat. She pointed to Buhari's infrastructure projects and a recent social welfare program as achievements from his term as president.

In the closing days of the campaign both Buhari and Abubakar have been busy on the campaign trail as the front-runners approach the election finish line. They have been criss-crossing the country to attend rallies where they are attracting enormous crowds, amid some outbreaks of violence.

When Buhari won against Goodluck Jonathan in the last election, it was the first time an incumbent had ever lost an election and there was a peaceful transition of power to the opposition leader. Nigeria returned to democracy in 1999 after decades of military rule.

It was a moment of great hope for the West African country's nascent democracy.

On Saturday, the eyes of the world will once again be on Nigeria to see if this presidential election -- the sixth since 1999 -- can really be free and fair and, more importantly, hold without widespread violence.