France, which already has the most centenarians of any European country, could be home to 13 times more people over the age of 100 by 2070, the national statistics agency Insee said Thursday.
In January 2016, there were around 21,000 centenarians living in France, almost 20 times more than in 1970, it said.
If current life-expectancy trends continue, this could rise to 270,000 by 2070.
Insee said France currently had the most centenarians of any country in Europe, ahead of Spain and Italy, partly because it has one of the largest populations but also because life expectancy among women is particularly high.
By 2070, almost one centenarian in three was expected to be a man, up from a ratio of one in six currently, the study said.
France was also home to the oldest verified person ever -- Jeanne Louise Calment, who died in 1997 aged 122 years and 164 days.
Many Britons and Americans have retired in France which, due to the slower pace of life and good healthcare system, is seen as an ideal country to get old in.
But a global survey in 2014 actually found that the UK and the US were better countries than France for your twilight years.
On the Global Age Watch 2014 index list of 96 nations, France came in at 16 (two higher than the previous year), while Britain notched the number 11 spot and the United States was ranked eighth. The usual global table-topping suspects Norway and Sweden took the number one and number two spots, with Afghanistan coming in last, just behind Mozambique.
In its summary of France the Global Age Watch index states that France performed the strongest in the area of "income security" (second in the world). It has one of the lowest poverty rates among the elderly and one of the highest relative welfare rates.
It ranks highly (seventh in the world) in the area of health but when it comes to perception of safety and satisfaction with public transport, France didn't score highly.