these are active or operational warheads. The 16,000 figure includes stockpiled reserves.
Every warhead’s weight is about 10 kilogram (2.68 pounds) of plutonium. Stock pile reserves in Russia amount more than 500 000 kilogram of fissible materials. In the USA production of fissible materials amount 550 000 kilogram (since 1945), total spending amount 3.9 trillion dollars.
US government (Al Gore) made a deal with Russia (V.Chernomyrdin) about purchase and sale 500 000 kilogram of Russian fissible materials for 20 billion dollars only. I can not imagine size of bribe(s) in such giant deal! There was big scandal in Russian media but the deal under name High Enriched Uranium - Low Enriched Uranium still execute (though listlessly). But it is another story where Russian staff thieves work with Americans in the intimate contact.