Hi, there are a number of things that you need to look at when cashing out your 401K. At 73 you are most likely receiving your required minimum distribution and if you're not then it's costing you by leaving it there.
Not sure if you're still working but if that is the case then you will have to check with your 401k plan administrator
With rare exceptions, all 401K withdrawals are taxable as ordinary income and if you are still working then in most cases, you’ll want to forget about an out-and-out withdrawal and work instead with your employer to arrange to take a loan from your 401(k) account. The law allows you to borrow up to half your vested balance or $50,000, whichever is less, without triggering taxes or a penalty.