## Elementary Algebra

$201=3\times67$.
Since the sum of digits of 201 is 3, 201 is divisible by 3. When we divide 201 by 3, we get 67. 67 is not divisible by any number except 1 and is therefore a prime number. Since 3 and 67 are prime factors, the prime factorization of 201 is $3\times67$.