"Anything may be crackable given enough time and resources."
Here is a good article that explains the differences of key size. Now imagine you exaggerate and create a 8192 key can it be cracked? Likely not. Are you safe? This all depends on the security of the system. If someone can compromise your machine and steal the key you made, the encryption strength is a moot point.
Considerations to take when asking a question like this would be to think as an attacker would.
- Can I crack this (likely not)
- How long would it take?
- How much would it cost me (wasted time+resources)?
- What would I gain putting in all this time, effort, and resources?
It is far cheaper to try and compromise the key, system, and or organization to get the key (install a keystroke logger, etc) than it is to try and brute force it.
When it comes to encryption, a lot of focus is spent on "can it be cracked" which is often a moot point when you think about the other factors. "Can this 16384 bit key be cracked on this insecure system." While it may not be cracked, it does not take away from the fact that other often overlooked factors may yield the key without the need to crack it. When someone performs penetration testing, if they can, they always copy SSL keys, screenshot them, then explain the dangers of not securing the key.
You are a billion dollar bank. You buy the biggest baddest safe on the planet... and You leave the key right next to the vault.