But closer to 1500 operationally deployed, and if they should launch any significant number of them, a substantial portion of the rest of the operationally deployed nukes in the world will be landing in Russia targeted and destroying any capacity they have to use any they have that weren't ready and deployed in the first strike.
Which is why if they use any significant number, even as a first strike, it will largely be for a counterforce strike doing the same thing to other nuclear powers, because who wants to be in a bunker without usable nukes when the guys you just nuked are in their bunker with usable nukes.
Having 6000 nukes ≠ 6000 nukes with operational readiness. If nuclear war were to break out, it is extremely unlikely that they could successfully use more than 1000 of those.
Not that that should make anyone feel any better about the situation, because even 1 nuke is too many.
Of course hindsight is always 20/20, but even before the war I had the arguments with some of my friends that modern Russia cannot produce anything at a modern world class level. How it can be possible if they pay 40k RUB to Senior Engineers working in military or space organizations, while you can get 90k RUB working as a "Sales Consultant" in electronics store. Add to this the record levels of corruption; inept leadership being assigned because of their political affiliation, rather than knowledge and experience (just check Rogozin) and you will find hard not to agree with me.
This incompetence manifests itself at all levels - starting from glorious leader Putin, who managed to convert pro-Russian Ukraine into the "NATO state" in less than 20 years; secret agents, who cannot kill a person without leaving a radioactive trace throughout the whole country and the success of "military operation" we see now.
Anyhow, obviously I'd prefer not to test my assumptions, but I believe that Russia has no hypersonic missiles - they planned to have it in production in summer, 2022 and we know what it means in Kremlin-speak. So far it's all cartoons, like their new 5th-gen aircrafts and MBTs. And I am quite confident that the vast majority of their warheads and missiles are long gone...