Factors of 1
The number 1 has exactly one factor: 1 itself. It is the only positive integer with a single factor, which makes it neither prime nor composite — mathematicians call it a unit. Because 1 divides every whole number, it appears in the factor list of every number.
All factors of 1
The number 1 has a single factor.
1
Properties of 1
| Number of factors | 1 |
|---|---|
| Sum of factors | 1 |
| Sum of proper factors | 0 |
| Prime factorization | — |
| Prime or composite? | Neither (unit) |
| Even or odd? | Odd |
| Perfect square? | Yes (1²) |
| Perfect cube? | Yes (1³) |
| Classification | Unit |
What makes 1 interesting
- The number 1 is a unit — neither prime nor composite. It is the only number with exactly one factor.
- Because 1 divides every whole number, it is a factor of every number in existence.
Related numbers
Numbers mathematically connected to 1.
Frequently asked questions about 1
What are the factors of 1?
The only factor of 1 is 1 itself. No other whole number divides 1 exactly.
Is 1 a prime number?
No. The number 1 is neither prime nor composite — it is called a unit, because it has only one factor.
What is the sum of the factors of 1?
Adding all the factors of 1 together gives 1. Excluding 1 itself, the proper factors sum to 0.
How many factors does 1 have?
1 has exactly one factor.
Explore more
Try another number in the factor calculator, break 1 down further with the prime factorization calculator, or compare 1 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.