Tokyo Olympics 2020: 121 days, 10,000 torchbearers, 47 regions, torch relay by the numbers

Tokyo: The Tokyo Olympic torch relay kicks off Thursday, a year and a day after it was postponed along with the Games because of the coronavirus pandemic.

The nationwide celebration, a massive undertaking, will be key to building momentum for the Games.

Here are some key facts and figures:

9,653 kilometres - The flame was lit using sunlight on 12 March, 2020 at the Temple of Hera in Greece's Olympia, more than 9,600 kilometres from the National Stadium in Tokyo where it will arrive for the opening of the Games on 23 July.

Tokyo 2020 was postponed soon after the flame was flown to Japan, but it has been kept alight for the past year.

After the postponement, it was briefly put on display in northeast Japan, but as COVID-19 cases rose, it was taken to a secret location.

It later reappeared for two months at Tokyo's Olympic Museum, a stone's throw from the National Stadium.

121 days - After setting off from Fukushima in northeast Japan, the torch will make its way through the country for around four months, or 121 days in total.

Fukushima and the surrounding Tohoku region were chosen as the starting point to showcase their recovery from the deadly 2011 quake, tsunami and nuclear disaster.

The public will not be allowed to attend the relay's starting ceremony on Thursday to prevent the spread of the coronavirus , with "simplified" festivities broadcast live online instead.

Zero cheers - Spectators lining the rest of the route will be allowed to watch the flame pass, but will have to wear masks, avoid crowding, and only attend segments of the relay near their home.

And there is a strict ban on cheering to avoid spreading infection, with fans urged to "support with applause or by using distributed goods".

Organisers have warned sections of the relay could be suspended if large crowds form.

47 Japanese regions - The torch will pass through all of Japan's 47 prefectures on its journey, from northern Hokkaido to subtropical Kagoshima and the island region of Okinawa.

It will take a circuitous route, first heading southwest and then back up to the northern regions before spiralling in on the capital.

The torch will spend around two days in each prefecture, where it will be carried on various short routes past landmarks and through towns and cities.

Each day, the final torchbearer of the day will hold a ceremony to transfer the flame to a bigger cauldron.

10,000 torchbearers - More than half-a-million people requested to carry the flame along part of the route in an application process in 2019.

Organisers have whittled that number down to approximately 10,000 torchbearers - ranging from Japanese sporting heroes to a girl whose grandfather participated in the torch relay when Tokyo last hosted the Games in 1964.

But there have been several high-profile withdrawals, with some citing scheduling conflicts and others concerned about the controversy over staging the Games during a pandemic.

200 kilogrammes - Each day, the flame will be deposited into a "celebration cauldron" weighing around 200 kilogrammes and standing 1.5 metres tall.

The rose-gold holder is shaped like a cherry blossom at the top -- like the Olympic torches used during the relay -- and 30 percent of it is recycled aluminium, originally used in temporary homes after the 2011 disaster.

118 years - The world's oldest living person, 118-year-old Kane Tanaka, will reportedly participate in the torch relay in the Fukuoka region.

The Guinness World Record holder is expected to carry the torch for about 100 metres while in a wheelchair pushed by family members.

Tanaka was born on 2 January, 1903 and reportedly enjoys studying maths and playing board games.