In Japan, you get a silver sake cup when you turn 100. Some Swiss cantons give engraved cowbells. Ireland gives a €2,540 "centenarian bounty" - not a once-off, you get it every year until you die.
I asked ChatGPT how many centenarians the Irish currently have, who is the oldest living example and who holds the longevity record. Apparently around 600 currently alive. As for examples, you can imagine records might be a bit patchy - and maybe private; a woman died last year aged 111, another born in 1911 died aged 113. Women worldwide average around 5 years longer lives than men.
More generally around the world, centenarians get a letter from the monarch/President/local Mayor and sometimes elaborate public celebrations/raucous parties. In Israel centenarians are invited to the President’s Residence for tea, group photos, and a party with other 100-year-olds. Sounds a riot.
The 600 Irish centenarians cost their taxpayers €1.5 million a year in total. Peanuts in overall terms. Good for them. Despite UK politicians' best efforts, we could probably afford that. Better than a letter/telegram/WhatsApp message from the King.
By the way, Japan (123 million population) has over 92,000 centenarians. That’s by far the highest per capita anywhere in the world. It's the sake.