>>11200874From Wikipedia:
A round number is mathematically defined as the product of a considerable number of comparatively small factors[1][2] as compared to its neighbouring numbers, such as 24 = 2*2*2*3 (4 factors, as opposed to 3 factors for 27; 2 factors for 21, 22, 25, and 26; and 1 factor for 23).
But colloquially it means something that ends in 0 or 5 in base ten.
>t. interested in number theory 
