Sakari Momoi world oldest person
Sakari Momoi receives a certificate of the World's Oldest Man by the Guiness World Records at a Tokyo hospital on August 20, 2014 in Tokyo, Japan. Getty Images

The world's oldest man has celebrated his 112th birthday with his family in Japan.

Sakari Momoi, a Japanese former agricultural chemistry teacher, became the world's oldest man after his predecessor Alexander Imich died at the age of 111 years and 124 days in 2014.

Momoi was born on 5 February 1903 in Fukushima city , just one day after Imich. He has five children and currently lives in a hospital in Tokyo.

He married the late Ms Tamiko in 1928.

Momoi responded with a smile as his family helped him celebrate on Thursday (5 February), his third son Hiroo, 66, told news agency Kyodo.

Momoi participates in some of the hospital's activities such as throwing a ball and practicing calligraphy, according to the family.

The world's oldest woman is Leandra Becerra Lumbreras, a 127-year-old Mexican who fought in the 1910 Mexican Revolution.

Lumbreras has 20 grandchildren, 73 great-grandchildren and 55 great-great grandchildren.

She attributes her long life to sleeping full days and keeping herself entertained by doing sewing and weaving.

Lumbreras, however, is not officially recognised as the world's oldest human, as she lost her birth certificate some 40 years ago. The Mexican authorities are in the process of supplying her with a new one. Until then Japan's Misao Okawa, aged 116, will hold the title.