Divide 210 by the smallest prime number (2):
210 ÷ 2 = 105
Divide 105 by the next smallest prime number (3):
105 ÷ 3 = 35
Divide 35 by the next smallest prime number (5):
35 ÷ 5 = 7
7 is already a prime number.
So, 210 = 2 × 3 × 5 × 7.
Prime factors of 210 are 2 × 3 × 5 × 7.