Factoring
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Each whole number N greater than 1 can be written
as the product of prime numbers . If N is already prime,
the equation just reads N=N. Otherwise, the way of writing N
as a product of primes is unique provided that the primes are
listed in increasing order. Here are the first 20 examples.
2 = 2
3 = 3
4 = 2 times 2
5 = 5
6 = 2 times 3
7 = 7
8 = 2 times 2 times 2
9 = 3 times 3
10 = 2 times 5
11 = 11
12 = 2 times 2 times 3
13 = 13
14 = 2 times 7
15 = 3 times 5
16 = 2 times 2 times 2 times 2
17 = 17
18 = 2 times 3 times 3
19 = 19
20 = 2 times 2 times 5