Q:

# What type of number has an odd number of factors?

A:

Only numbers that are perfect squares have an odd number of positive factors. All other types of numbers have an even number. However, if negative factors are included, then all numbers have an even number of factors.

## Keep Learning

Factors occur in pairs because pairs of factors multiplied together produce the factored number. For example, 12 is produced by multiplying 1 and 12, or 2 and 6, or 3 and 4, so 12 has six different factors. With a perfect square, there is always one factor that produces the number when multiplied by itself. For example, 16 is produced by multiplying 1 and 16, or 2 and 8, or 4 and 4, so there are only five different factors for 16.

Sources:

## Related Questions

• A: To find the greatest common factor of two or more numbers, find the factors of each number, then circle the shared factors. Choose the greatest factor that... Full Answer >
Filed Under:
• A: The numbers up to 100 that are perfect squares are 1, 4, 9, 16, 25, 36, 49, 64, 81 and 100. A perfect square is a number that is the result of a smaller nu... Full Answer >
Filed Under:
• A: The magnitude, or modulus, of a complex number in the form z = a + bi is the positive square root of the sum of the squares of a and b. In other words, |z|... Full Answer >
Filed Under:
• A: The following numbers under 100 have the most factors: 60, 72, 84, 90 and 96. They each have a total of 12 factors, including the number one and the number... Full Answer >
Filed Under:
PEOPLE SEARCH FOR