Factors of 55
There are 4 factors of 55 — the full list is below, with factor pairs, prime factorization, and divisibility notes.
Factors of 55
1, 5, 11, 55
Factor pairs of 55
- 1 × 55
- 5 × 11
Prime factorization of 55
55 = 5 × 11
Number facts
- 55 is a composite number.
- 55 has 4 factors.
- 55 is not a perfect square.
- The sum of all factors of 55 is 72.
Divisibility rules that apply to 55
- 55 is divisible by 5 because it ends in 0 or 5.
Check another number
How the factors of 55 are calculated
To find the factors of 55, every whole number from 1 up to the square root of 55(about 7.42) is tested for even division. 55 is odd, and it divides evenly by 5, 11. Written as a product of primes, 55 = 5 × 11, which confirms every factor above is a combination of those prime building blocks.
Frequently asked questions about 55
How many factors does 55 have?
55 has 4 factors: 1, 5, 11, 55.
Is 55 a prime number?
No. 55 is composite because it has factors other than 1 and itself.
What are the factor pairs of 55?
The factor pairs of 55 are 1 × 55, 5 × 11.
What is the prime factorization of 55?
The prime factorization of 55 is 5 × 11.