I am wondering if there is a term for a number which is only divisible by its square root, one and itself? For examle $25$ can be divided by $1, 5$ and $25$. And $169$ with $1, 13$ and $169$.
I am not a mathematician (potentially can't even spell it) just came across this thought and wondered if such a term existed for these kind of numbers or perhaps there are too few examples or no use for defining them.
Anyway any feedback would be much appreciated!
Thanks.
Well, they are called "squares of prime numbers". Indeed (if you require that the square root of such a number is an integer) they must have the form $k^2$, and if $k$ is not prime, then take $p|k$ a prime dividing $k$, and such a $p$ will divide $k^2$.