1,729 is the “taxicab number”; the smallest number that is the sum of two cubes in two different ways: 1000+729 = 1728+1
17,290 is 10 times the taxicab number.
36,100 is the sum of the first 19 cubes.
50,021 is a prime number, meaning that it has no factors except one and itself.
109,376 is an automorphic number; if you multiply it by itself any number of times, the same six digits remain at the end.