n = 10!; fa = factor(n);
sumdiv(n, d, eulerphi(d))
sumdiv(n, d, d^2)
sumdiv(fa, d, eulerphi(d))
sumdiv(fa, d, d^2)
sumdivmult(n, d, eulerphi(d))
sumdivmult(n, d, d^2)
sumdivmult(fa, d, eulerphi(d))
sumdivmult(fa, d, d^2)

sigma2(x) = sigma(x,2);
sigma3(x) = sigma(x,3);
core2(x) = core(x,1);
fun = [ispowerful, moebius, core, core2, omega, bigomega, eulerphi, numdiv, sigma, sigma2, sigma3];
for(i=1,#fun, print(fun[i](fa)))

test(fa)= for(i=1,#fun, print(iferr(fun[i](fa),E,E)));
test(0)
test(factor(0))
test(-2)
test(factor(-2))

fa = factor(1);
for(i=1,#fun, print(fun[i](fa)))
divisors(fa)

fa = factor(0);
ispowerful(fa)
core(fa)
core2(fa)
divisors(fa)

fa = [5!, factor(5!)];
core2(fa)
divisors(fa)

n = x^2*(x+1)^3*(x+2)^5; fa = factor(n);
sumdiv(n, d, d)
sumdiv(fa, d, d)
sumdivmult(n, d, d)
sumdivmult(fa, d, d)

\\#1664
divisors([1,2])
