Nearly a fifth of people living in the UK are expected to celebrate their 100th birthday, the Government has predicted.
More than 10 million of the UK's current residents, the equivalent of 17% of the population, are expected to live until they are at least 100, according to the Department for Work and Pensions (DWP).
Three million of these are currently aged under 16, while 5.5 million are between 16 and 50 and 1.3 million are between 51 and 65. A further 875,000 of the projected centenarians are aged over 65 and already retired.
It is estimated that by 2066 there will be at least 507,000 people in the UK aged 100 or over, including 7,700 super centenarians who are aged 110 or over.
The figure is well up on the 11,800 people in the UK who are currently at least 100, while there are less than 100 people who are aged more than 110.
The number of people aged over 100 is expected to nearly double between 2030 and 2035, when it is projected there will be 97,300 centenarians in the UK. It is then expected to more than double again during the next decade, to stand at 202,100 by 2045.
The DWP projects that by 2080, there could be 626,900 people in the UK aged 100 or more, 21,000 of whom will be at least 110.
But while the increase in longevity is good news for individuals, it is likely to put considerable pressure on the country's pensions systems, as people face spending a growing proportion of their life in retirement.
Pensions Minister Steve Webb said: "These staggering figures really bring home how important it is to plan ahead for our later lives. Many millions of us will be spending around a third of our lives or more in retirement in the future.
"That's why we are reforming the pension system to make it sustainable for the long term, making sure people can look forward to a decent state pension when they retire, and helping millions save into a workplace pension, many for the first time."