There is a number, which is not only a divisor of 45, but also a multiple of 45. This number is______ Let's decompose this number. The prime factor is______ .

There is a number, which is not only a divisor of 45, but also a multiple of 45. This number is______ Let's decompose this number. The prime factor is______ .

(1) According to the definition of divisor and multiple, 45 is not only its largest divisor, but also its smallest multiple; (2) 45 = 3 × 3 × 5