Find the LCM using the division method.

$21,28,36,45$

Find the HCF and the LCM of the following numbers and verify that the product of numbers $=$HCF $\times$ LCM.

$\mathrm{54,444}$

Find the HCF and the LCM of the following numbers and verify that the product of numbers $=$HCF $\times$ LCM.

$81,82$

Find the HCF and the LCM of the following numbers and verify that the product of numbers $=$HCF $\times$ LCM.

$270,450$

Find the HCF and the LCM of the following numbers and verify that the product of numbers $=$HCF $\times$ LCM.

$576,720$