I came across this the other day
В России живут всего 70 миллионов человек?
Translation
В России живут всего 70 миллионов человек?
It looks at food production and consumption numbers to check the numbers on Russia's population. I guess an accepted standard of grain consumption for a country that doesn't have food scarcity is about 1 tonne per person per year. This includes grain that goes into animal feed, alcohol production, and other uses. In the US that would also include ethanol production for motor fuels, but that is probably more minimal in Russia. Though Russians drink more distilled ethanol than Americans.
In 2018 Russia produced 100 million tonnes of grain and exported 40 million, which leaves 70 million consumed domestically. The article points out that the 1 tonne per person is probably high for many countries. It is that for the US.
I looked up some other statistics mentioned in the article and found some interesting numbers. In 2018 there were about 57 million cars registered in Russia and in 2021 there were 146 million cell phones active!
Telecommunication in Russia
Even if Russia's reported population numbers are accurate, most people have at least 2 cell phones.
I was also thinking about an essay Science Fiction author Robert Heinlein wrote about his trip to the USSR in 1960. He and his wife toured Moscow and took some time one day to sit on a park bench and "compare notes". They knew being one of the few western tourists they were probably being watched so they chose an open area to discuss what they were thinking. He had been looking at the transportation logistics and had come to the conclusion that Moscow must be 1/2 the size the Soviets claimed. His wife had been looking at other factors and had come to the same conclusion.
He was left pretty convinced the Soviets were lying about the population of the USSR.
I also came across something a few weeks ago that Rosstat quit actually measuring vital statistics like births and deaths some years ago and they have been reporting made up numbers. Additionally the supposedly measured numbers may have been cooked for a while. The conclusion was that Russia's under 20 population may be much smaller than the official numbers, and the official numbers don't look good for Russia's long term economic health.
I doubt that Russia's population is actually 70 million. But less than 1/2 tonne per person per year is probably a bit low for a country that eats meat, probably doesn't make ethanol for motor fuel, but does make a lot of alcohol for human consumption.
I would guess the population of Russia might be as low as 100 million. It probably isn't the 145 million that Russia claims it is.