We have 5 vowels and 21 consonants.

select : 2 vowels and 2 consonants

We can choose 2 vowels from 5 in ^{5}C_{2} ways = 10 ways

We can choose 2 consonants from 21 in ^{21}C_{2} ways = 210 ways

Now these selected 4 letters can be arranged in 4! ways = 24 ways

By fundamental theorem,

total number of ways(words) = 10*210*24

= 50400