If it is the number of discrete objects, as in 'The average number of dogs per family in the town of Bamberg is 1.0001', then yes, it is plural. Each family has, on average, 1.0001 dogs.
20002
10001
10001 = 73 x 137
Binary of 17 is 10001. 1710 = 10001 2 1810 = 100102
10001
If 10001 = 19, it is in an irregular non-integral base. (In binary, 10001 = 17, 10011=19, and 10100 = 20.)
10001 + 567 - 900 = 9668
echo "1 101 1010 10001";
The number 10001 is "ten thousand one" (also ten thousand and one).
20002 and 0.5, or 10001 and 1 or 5000.5 and 2 etc
10001
13123233