Number A=2*2*3*5*a, Number B=2*3*7*a, (A, B, and a are all natural numbers greater than 1), what is the least common multiple of A and B?
甲数=2*2*3*5*a，乙数=2*3*7*a，(甲、乙、a都是大于1的自然数)，甲乙两数的最小公倍数是多少a
<result>420</result>