If numbers reproduced like biological lifeforms, within a relatively few generations all numbers would be even.
After all, the only way you can get an odd number as a result of a multiplication is if both 'parents' are odd. Presuming that any even numbers exist, natural interbreeding will shortly dispose of all but the most hard-core 'racial purity' odd-ites. Eventually, they'll die out through attrition and inbreeding.
It's a good thing for established mathematics that numbers don't breed.
-Matthew D. Fuller