**The prime factorization of 35 is 5 and 7.** Prime factors are numbers that are only divisible by themselves and one. While every number is divisible by one, most mathematicians do not consider it as a prime factor.

Deriving the prime factors of a number is helpful in determining least common multiples and greatest common factors. The concept of least common multiple helps students learn to add fractions having different denominators. Greatest common factors are useful in reducing fractions to their standard form. Two is a prime factor of every even number and is the most common prime factor found.