If a radical is added with two independent words (the two independent words may be the same, such as "light"), it is 254 * 280 * 280 =19913600 (species).
If radicals or single characters can be combined in pairs (that is, radicals can be added to radicals or single characters can be added to single characters), that is
(254+280) * (254+280) = 285156 (species)
The above can be calculated by permutation and combination formula, but because the calculation is simple and the permutation and combination formula is not fun, it is more convenient to calculate directly.