Appaz Iliev, who had eight children, 35 grandchildren and 34 great-grandchildren, previously said the secret to his long life was going to bed at 7pm and getting 11 hours sleep a night.
The “loving old man” from Russia also attributed his longevity to avoiding alcohol, smoking and medication.
Paying tribute, official Yunus-Bek Evkurov, said: “Our long living man, the eldest citizen of Russia, Appaz Iliev has died at the age of 123.
“Appaz lived through epochs and generations, raising eight children.
“He had 35 grandchildren, 34 great-grandchildren and several great-great-grandchildren.
“He remained a kind and loving old man who loved this life.
“I know this myself because I met him several times.”
Appaz went to work aged seven as a shepherd, and fought for the Red Army in the Russian Civil War 1917-22, it is claimed.
But at the age of 45 he was deemed too old to fight in the Second World War and instead became a tractor driver.
In 1944 he was deported by Stalin along with other ethnic Ingush people to Kazakstan where he lived in abject poverty in internal exile.
If his age was correct – and his birth records do not survive – he would have been older than than the officially verified longest-living man – Jiroemon Kimura (1897–2013) of Japan – who died at 116 years, 54 days.
Apaz shunned television and never smoked or drank alcohol, and kept away from doctors and medication as much as possible although at the age of 121 he underwent eye surgery because of a cataract, it is claimed.
He ate only eat only fresh vegetables from his own garden, and local meat in his remote village of Guli in the Russian Caucasus Mountains.
He drank dairy milk and fresh spring water.
Above all, he made sure he got 11 hours sleep each night, retiring each day at 7pm.
“Value what you have and share it with others”, he advised his large family.
He spoke his native Ingush language and although he was “Russia’s oldest man” he never learned the Russian language.
Born in March 1896 under the last Tsar Nicholas II, he was a shepherd in the mountains aged seven and left “absolutely alone” to look after the sheep.
He worked as a shepherd most of his life, having up to 800 animals in his herd, say reports.
Several years ago he recalled: “The first time my parents sent me alone to shepherd sheep at the age of seven.
“I cried all day long because I was so afraid. There were many soldiers in the mountains, I was so scared.
“It is over 100 years ago but I still remember that fear.”
At the age of 115 he could still mount a horse and went to the fields to tend the cattle.
He was still mowing grass until the age of 119, say local reports.
At the same age it was reported that “he still has all his own teeth”.
Apaz claimed his grandfather also lived to 120, having remarried at 80 and fathered eight additional children.
His wife named Madinat died in 2014.
The couple met in Kazakhstan when he was on his tractor and saw another tractor driving the wrong way.
He followed it and found the woman driver had fallen asleep at the wheel.
He jumped onto her tractor and they fell in love.
Appaz has been listed in the Russian Book of Records as the country’s oldest man since 2015.
Before the veteran’s death, his grandson Mustafa Iliev, 33, said: “Grandpa tells us the first thing is to be active, to be in motion.
“He loves to say: ‘If you see some man in need of help – don’t turn your head away. Jump up and help him.
“Looking at you, people should say – well done, whose son is he? What family is he from? – because you are in charge not only of your own dignity but of the dignity of your whole family’.”
“His second piece of advice is to value what we have and to share it with others.
“He often kills his animal for meat and shares it with poor people.
“When living in exile in Kazakhstan, our family was often hungry, we know all about life in poverty.
“They worked at the fields but could not eat the crops.
“Every day when they were going home, their pockets and hats were checked for stolen corn.
“But soon they learned to wear high boots and managed to hide some corn in them… this is how they survived and fed the family.”
Many people are deemed to live to exceptional ages in the Caucasus – but birth records seldom survive so their great ages are impossible to verify.