Determine if 372645 is divisible by 45.

To determine if 372645 is divisible by 45, we test it for divisibility by 5 and 9 both (since 45 = 5 × 9 and 5, 9 are co-prime).

The number 372645 has digit 5 at the unit's place, so it is divisible by 5.

Sum of digits = 3 + 7 + 2 + 6 + 4 + 5 = 27, which is divisible by 9, so 372645 is divisible by 9.

Since 5 and 9 are co-prime, the number 372645 is divisible by their product, i.e., by 45.

Hence, 372645 is divisible by 45.