Prime factor of 1245

First, we identify the smallest prime factor of 1245:

1. Check if 1245 is divisible by 2: Since 1245 is odd, it is not divisible by 2.
2. Check divisibility by 3:
1 + 2 + 4 + 5 = 12
which is divisible by 3, so 1245 is divisible by 3.
Dividing gives:
1245 \div 3 = 415

3. Check if 415 is divisible by 5: Since 415 ends in a 5, it is divisible by 5.
Dividing gives:
415 \div 5 = 83

4. Determine if 83 is a prime number: 83 is not divisible by 2, 3, 5, or 7 (prime numbers up to the square root of 83), so 83 is a prime number.

Thus, the prime factors of 1245 are:
3, 5, 83

**Answer: 3, 5, 83**