Check out this brief resource which offers a list of known anti-divisors or unbiased non-divisors. Author includes recommended reading.

Check out this essay which discusses a factoring device built by French amateur, E.O. Carissan, circa 1919. Author includes color photographs of the machine.

Check out different courses and experiments for grade school students and teachers. Resource offers the factors of numbers between 1 and 500.

Check out this resource offering essays and links to known major factoring algorithms, including Shank's square, Shor's, and Euler's.

Small Web-based application is designed to factor a formula into its irreducible or prime factors. Includes suggested resources.

Have a look at an available Java application designed to calculate 20 or 30-digit factors of numbers and numerical expressions up to 1000 digits long.

Author of this mathematical resource provides a graph of collected known amicable pairs. Includes lists and statistics.

Author for this resource uses ECM factoring on numbers of the form n!+-1. Includes tables and recommended reading.