Determine if 25110 is divisible by 45. [Hint : 5 and 9 are co-prime numbers. Test the divisibility of the number by 5 and 9.]

The prime factorization of 45 = 5 x 9
25110 is divisible by 5 as 0 is at its unit place
25110 is divisible by 9 as sum of digits is divisible by 9.
Therefore, the number must be divisible by 5 x 9 =45