Number of entries in the page table is same as number of pages in the LAS. Except for inverted page tables, it is the number of frames in PAS.
Here number of pages = $\frac{VAS}{page size}$ = $\frac{2^{32}B}{4 KB}$ = $\frac{2^{32}}{2^{12}}$ = $2^{20}$ which is 1 million
You should not convert bytes to words as default is byte addressable. Also word size is not always 32 bits, it varies as per the processor architecture. It will be explicitly mentioned if you have to do the conversion of bytes to words or not.
Hope this helps!