C++ :

#include <cstdio>
int main(){
    long long n;
    if(scanf("%lld",&n)!=1) return 0;
    int first=1;
    for(long long d=2; d*d<=n; d++)
        while(n%d==0){ printf(first?"%lld":" %lld", d); first=0; n/=d; }
    if(n>1){ printf(first?"%lld":" %lld", n); first=0; }
    printf("\n");
    return 0;
}