Factor Calculator

Factors of 221

The factors of 221 are 1, 13, 17, and 221. In total, 221 has 4 factors. Its prime factorization is 13 × 17, and the sum of all its factors is 252.

All factors of 221

Here are all 4 factors of 221, listed from smallest to largest.

11317221

Factor pairs of 221

These 2 pairs of whole numbers each multiply to give 221.

1 × 221 = 221
13 × 17 = 221

Prime factorization of 221

Dividing 221 by the smallest prime at each step gives its prime factorization:

221 ÷ 13 = 17
17 ÷ 17 = 1
Result: 221 = 13 × 17 = 13 × 17

The distinct prime factors of 221 are 13, 17. To factorize any other number, use the prime factorization calculator.

Factor tree of 221

A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.

Factor tree of 2212211317
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 221

Number of factors4
Sum of factors252
Sum of proper factors31
Prime factorization13 × 17
Prime or composite?Composite
Even or odd?Odd
Perfect square?No
Perfect cube?No
ClassificationDeficient

What makes 221 interesting

  • 221 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 2 different ways.
  • 221 is a deficient number: its proper factors sum to 31, which is 190 less than 221 itself.

How to find the factors of 221 yourself

Divide 221 by each whole number starting from 1. Whenever the division leaves no remainder, both the divisor and the quotient are factors. You only need to test up to √22114.87, because every factor above that pairs with one below it.

221 ÷ 1 = 221
221 ÷ 13 = 17

Reading both columns gives every factor: 1, 13, 17, 221. The factor calculator does this automatically for any number.

Frequently asked questions about 221

What are the factors of 221?

The factors of 221 are 1, 13, 17, and 221. That is 4 factors in total, counting both 1 and 221.

Is 221 a prime number?

No, 221 is not prime — it is a composite number with 4 factors. A prime number has exactly two factors, but 221 is also divisible by 13.

What is the prime factorization of 221?

The prime factorization of 221 is 13 × 17. Written out in full: 13 × 17 = 221. Its distinct prime factors are 13, 17.

What two numbers multiply to give 221?

There are 2 pairs of whole numbers that multiply to 221: 1 × 221, 13 × 17.

What is the sum of the factors of 221?

Adding all the factors of 221 together gives 252. Excluding 221 itself, the proper factors sum to 31.

Is 221 a perfect square?

No, 221 is not a perfect square. There is no whole number that multiplies by itself to give 221. The nearest perfect squares are 196 and 225.

What is the largest factor of 221 other than itself?

The largest factor of 221 apart from 221 itself is 17, since 221 ÷ 17 = 13.

How many factors does 221 have?

221 has 4 factors: 1, 13, 17, and 221. You can verify this from the prime factorization 13 × 17: add 1 to each exponent and multiply, giving 2 × 2 = 4.

Explore more

Try another number in the factor calculator, break 221 down further with the prime factorization calculator, or compare 221 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.