To find the prime factorization, divide 125 by only prime numbers. Remember that prime numbers are whole numbers greater than 1 that are only evenly divisible by themselves and 1 . { 2 , 3 , 5 , 7 , 11 , 13 , 17 , 19 , 23 , 29 , 31 , 37 , 41 , 43 , 47 , 53 , etc.} Since 125 ends in 5 , it is evenly divisible by 5 , which is a prime number. (How convenient!) 125 ÷ 5 = 25 25 now has to be factored into its prime factors. 25 = 5 ⋅ 5 So, the prime factorization of 125 is 125 = 5 ⋅ 5 ⋅ 5 = 5 3
