840=2*2*2*3*5*7
32 is not a factor of 840.
7*5*4*3*2 Is the longest factor string of 840
Stings with four factor that make 840
840 = 2 x 2 x 2 x 3 x 5 x 7 OR 23 x 3 x 5 x 7
Multiples of 840
Prime factors are 2, 2, 2, 3, 5, 7 Other factors are combinations of the primes, i.e. 2 x 2 = 4 2 x 3 = 6 2 x 2 x 2 = 8 2 x 5 = 10 2 x 2 x 3 = 12 2 x 7 = 14 3 x 5 = 15 2 x 2 x 5 = 20 3 x 7 = 21 2 x 2 x 2 x 3 = 24 2 x 2 x 7 = 28 2 x 3 x 5 = 30 5 x 7 = 35 2 x 2 x 2 x 5 = 40 2 x 3 x 7 = 42 2 x 2 x 2 x 7 = 56 2 x 2 x 3 x 5 = 60 2 x 5 x 7 = 70 2 x 2 x 3 x 7 = 84 3 x 5 x 7 = 105 2 x 2 x 2 x 3 x 5 = 120 2 x 2 x 5 x 7 = 140 2 x 2 x 2 x 3 x 7 = 168 2 x 3 x 5 x 7 = 210 2 x 2 x 2 x 5 x 7 = 280 2 x 2 x 3 x 5 x 7 = 420
3 x 5 x 7 x 8 2 x 6 x 7 x 10
840/7 = 120
120
120 x 7 = 840 840 - 7 = 833
The GCF of 320 and 840 is 40.