How to find the factors of 441
Test every whole number from 1 up to the square root of 441 (√441 ≈ 21.000). Each number that divides evenly gives you two factors at once: the divisor and the quotient.
- 441 ÷ 1 = 441 — so 1 and 441 are factors
- 441 ÷ 2 = 220.5 — not a whole number
- 441 ÷ 3 = 147 — so 3 and 147 are factors
- 441 ÷ 4 = 110.25 — not a whole number
- 441 ÷ 5 = 88.2 — not a whole number
- 441 ÷ 6 = 73.5 — not a whole number
- 441 ÷ 7 = 63 — so 7 and 63 are factors
- 441 ÷ 8 = 55.125 — not a whole number
- 441 ÷ 9 = 49 — so 9 and 49 are factors
- 441 ÷ 10 = 44.1 — not a whole number
- 441 ÷ 11 = 40.091 — not a whole number
- 441 ÷ 12 = 36.75 — not a whole number
- 441 ÷ 13 = 33.923 — not a whole number
- 441 ÷ 14 = 31.5 — not a whole number
- 441 ÷ 15 = 29.4 — not a whole number
- 441 ÷ 16 = 27.563 — not a whole number
- 441 ÷ 17 = 25.941 — not a whole number
- 441 ÷ 18 = 24.5 — not a whole number
- 441 ÷ 19 = 23.211 — not a whole number
- 441 ÷ 20 = 22.05 — not a whole number
- 441 ÷ 21 = 21 — so 21 and 21 are factors
Collecting both numbers from every successful division gives the complete list: 1, 3, 7, 9, 21, 49, 63, 147 and 441.
Prime factorization of 441
Divide by the smallest prime that fits, and keep going until the quotient is 1:
The primes you divided by give 441 = 3² × 7². From the exponents you can also count the factors without listing them: (2 + 1) × (2 + 1) = 9.
Properties of 441
- 441 is a composite number.
- The sum of all its factors is 741; the sum of its proper factors (excluding 441) is 300, which makes it a deficient number (its proper factors add up to less than itself).
- 441 is a perfect square: 21 × 21. Perfect squares always have an odd number of factors.
- Multiples of 441 include 882, 1,323, 1,764, 2,205 and so on.
Factors vs. multiples
Factors of 441 are the numbers that divide into it; multiples of 441 are the numbers it divides into. Every number has a limited set of factors but infinitely many multiples. To work with any other number, use the factors calculator, or find shared factors with the GCF calculator.
Frequently asked questions
What are the factors of 441?
The factors of 441 are 1, 3, 7, 9, 21, 49, 63, 147 and 441. Each of these divides 441 with no remainder.
How many factors does 441 have?
441 has 9 positive factors, which form 5 factor pairs. Counting negative factors as well doubles that to 18.
What is the prime factorization of 441?
441 = 3² × 7². Its distinct prime factors are 3 and 7.
Is 441 a prime number?
No. 441 is composite because it has 9 factors, more than the two a prime number has.