Factorisation of letters is not defined.
The prime numbers (factors) of 70 are: 2,5,7
The prime numbers (factors) of 105 are: 3,5,7
The prime numbers (factors) of 172 are: 2 and 43
The prime numbers (factors) of 50 are: 2 and 5
The prime numbers (factors) of 44 are: 2 and 11
The prime numbers (factors) of 225 are: 3 and 5
The prime numbers (factors) of 108 are: 2 and 3
The prime numbers (factors) of 250 are: 2 and 5
The prime numbers (factors) of 405 are: 3 and 5
The prime numbers (factors) of 115 are: 5 and 23
The prime factors of 210 are 2x3x5x7.
The prime factors of 84 are 2x2x3x7.