This Thursday marks the end of the 2010 Hajj in Saudi Arabia. The annual pilgrimage to Mecca is a required rite that must be completed by all Muslims at least once in their lives, unless they are physically or financially unable. According to Saudi officials, this year's Hajj, which began on Nov. 14, drew 2.8 million believers from all over the world. (Watch an Al Jazeera report about this year's Hajj.) Here are some other enlightening stats:

Number of countries from which pilgrims began the trek this year

1.57 billion
Number of Muslims worldwide as of 2009

Number of holy spots through which pilgrims must travel, including Mecca, Mina, Mount Arafat, and Muzdalifah

Height in feet of the Makkah Clock Royal Tower, a skyscraper in Mecca overlooking the Grand Mosque which features what is said to be the world's biggest clock (bearing the inscription "God is Great" in Arabic)

Height in feet of the world's tallest building (the Burj Tower in Dubai)

$1.8 billion
Cost in dollars of Saudi Arabia's newly opened Mecca Metro train that pilgrims used to travel the 16 kilometers between Mina and Arafat

Estimated number of pilgrims the Mecca Metro will have transported during this year's Hajj. When operating at full capacity, next year, the rail will move an estimated 500,000 people every six hours.

Number of months two men spent bicycling from South Africa to Saudi Arabia this year

Estimated number of kilometers they traversed every day in order to arrive by Nov. 14

Number of Nigerian nationals who died during this year's pilgrimage

Number of Nigerian babies born during the 2010 Hajj

Number of pebbles pilgrims must throw to symbolize their rejection of Satan's temptations during the final ritual of the Hajj

Number of cellular towers recently erected around Mecca to help improve pilgrims' phone reception

The price in dollars of Magnicode Inc.'s "Hajj — Pilgrimage to Mecca" app for the iPhone, iPod Touch, and iPad

Sources: Pew Forum; Bloomberg; Guardian; About; Al-Jazeera; Nigerian Tribune; Al-Arabiya; Toronto Star; iTunes Store.