1, 7, and 49 are the factors of 49. The numbers that divide into a given number evenly and leave no residue are said to be the factors of that number. There are always two factors: one and the actual number, in this case 49.
The fact that 49 is a square means that it can be divided by itself to produce 49, which equals the number seven. The square root of 49 is seven. Seven is a prime number, which means that only one and itself equally divide it.
Therefore, the prime factorization of 49 is 7 x 7 or 72. Finding the prime numbers that add up to a given number is the process of determining its prime factors.