A factor is a number that divides another number exactly, without leaving any remainder. In other words, if you can divide a number nnn by another number xxx and the result is a whole number with no remainder, then xxx is a factor of nnn

. Key points about factors:

• Factors are always positive whole numbers (integers), not fractions or decimals

• Every number has at least two factors: 1 and the number itself

• If a number has more than two factors, it is called a composite number; if it has exactly two factors (1 and itself), it is a prime number

• Factors come in pairs that multiply to give the original number. For example, the factors of 12 are 1, 2, 3, 4, 6, and 12, and they pair as (1,12), (2,6), and (3,4)

• Square numbers have an odd number of factors because one factor pair is the same number multiplied by itself (e.g., 25 has factors 1, 5, and 25)

In summary, a factor is a divisor of a number that divides it evenly, and understanding factors is fundamental in arithmetic, prime factorization, and number theory