By the numbers: Facts and figures about Queen Elizabeth II

This photo, taken April 16, 2017, shows Britain’s Queen Elizabeth as she leaves the Easter Sunday service in Windsor Castle, in Windsor England. Queen Elizabeth celebrates her 91st birthday on Friday, April 21, 2017. (Pool file photo by PETER NICHOLLS via AP)

LONDON — Queen Elizabeth II, who celebrates her 91st birthday on Friday, is Britain’s oldest-ever monarch and the world’s longest-reigning king or queen.

Here’s a look at some milestones and numbers related to the queen:

Elizabeth has reigned for 65 years and 75 days. On Sept. 9, 2015, she became Britain’s longest-reigning monarch, passing her great-great-grandmother Queen Victoria.

She is the world’s longest-reigning living monarch since the death of Thailand’s King Bhumibol Adulyadej last year.

She has had 13 British prime ministers serve during her reign, from Winston Churchill to Theresa May.

She has met 12 US presidents, from Herbert Hoover (after he left office) to Barack Obama, more than a quarter of all the US presidents since Independence. She is due to host President Donald Trump for a state visit later this year.

She has traveled more than 1 million miles (1.6 million kilometers) on official trips, visiting 106 countries.

She has visited Canada 22 times – the largest number of trips to any nation.

She has four children, eight grandchildren and five great-grandchildren.

She has cut back on her official duties in the last few years, but Elizabeth still conducted 332 official engagements in 2016.