BUILT-IN MATHEMATICA SYMBOL

FactorInteger

FactorInteger[n]
gives a list of the prime factors of the integer n, together with their exponents.

FactorInteger[n, k]
does partial factorization, pulling out at most k distinct factors.

Details and Options Details and Options

For negative numbers, the unit is included in the list of factors.
FactorInteger also works on rational numbers. The prime factors of the denominator are given with negative exponents. »
The last element in the list FactorInteger[n, k] gives what is left after the partial factorization.
FactorInteger[n, GaussianIntegers->True] factors over Gaussian integers. »
FactorInteger[m+I n] automatically works over the Gaussian integers.
When necessary, a unit of the form , {I, 1}, or {-I, 1} is included in the list of factors.
FactorInteger[n, Automatic] pulls out only factors that are easy to find.
FactorInteger uses PrimeQ to determine whether factors are prime.