How to split a file with 250k columns vertically?

Question

I need to split a file with 250k based on the size (preferable) or number of columns to several (~5) chunks. I am aware of split command for row-wise splitting, but don't know if there is any similar function to split column-wise. The number of columns in my file are not even, so the chunks cannot have equal number of columns.

Input:

AA BB CC DD EE FF GG HH II JJ KK LL MM
NN OO PP QQ RR SS TT UU VV WW XX YY ZZ

Desired output:

File1

AA BB CC DD        
NN OO PP QQ

File2

EE FF GG HH
RR SS TT UU

File3

II JJ KK LL MM
VV WW XX YY ZZ 

Answer 1

Using awk, you can adjust n to the number you expect.

awk '{for (i=1;i<=NF;i++)
         printf (i%n==0||i==NF)?$i RS:$i FS > "File" int((i-1)/n+1) ".txt"
      }' n=5 file