According to the divisibility rule of 45 if the last digit of a number is divisible by 5 and the sum of the digits is divisible by 9, then the number is divisible by 45.

45 = 5 × 9

Factors of 5 = 1 and 5

Factors of 9 = 1, 3 and 9

Therefore, 5 and 9 are co-prime numbers,

As the last digit of the number is 0 so it is divisible by 5.

Sum of the all digits = 2+5+1+1+0 = 9

As the sum of the digits is divisible by 9 so this number is also divisible by 9.

So, the number is divisible by 5 and 9, it is also divisible by 45.