DAKAR (Reuters) - Democratic Republic of Congo has delayed a much-anticipated presidential election scheduled for Dec. 23 by one week after the electoral body said it could not organize the vote in time.

The national electoral commission (CENI) has faced a daunting challenge rolling out the ballot across the vast Central African country ahead of what is meant to be Congo’s first democratic transfer of power.

On Thursday, it cited a fire that destroyed ballot papers as the main reasons for the delay.

Here is a look at the election in numbers.

* 0: the number of Congo’s democratic transfers of power since independence from Belgium in 1960.

* 21: the number of official candidates.

Among the 21, only three are considered serious contenders: Kabila’s preferred successor, Emmanuel Ramazani Shadary; Felix Tshisekedi, president of Congo’s largest opposition party, and opposition businessman Martin Fayulu.

* 75,000: the number of polling stations.

Each polling station is supposed to process no more than 600 voters.

* 40 million: the number of registered voters.

Half of Congo’s population of 80 million is registered to vote.

* 2.3 million: the approximate number of square kilometers covered by Congo - around 900,000 square miles.

Congo is Africa’s second-largest country and is blanketed by the world’s second-biggest rainforest. Travel is hampered by a lack of roads and transport infrastructure.

* 15,358 and 19,640: the number of candidates for the national and provincial assemblies.

Besides the presidential race, voters will also elect representatives to the provincial and national assemblies. There are 500 and 715 representatives in each of them respectively.

* 105,000: the number of voting machines.

For the first time, votes will be cast on tablet-like electronic machines rather than on paper ballots. The new system has proved controversial, as opposition candidates say the machines are vulnerable to fraud and could be compromised by unreliable power supplies.

The CENI has promised that the results will tabulated manually by counting paper print-outs of the choices voters select on the machines.

* 512,000: the number of “operating agents”.

The CENI will be dispatching over half a million people across the country to manage the electoral process. They have 150 military trucks, and also planes and helicopters at their disposal to access harder-to-reach areas.