Is 1 a Prime Number?
Is 1 prime?
No
1 = 1 (divisible by 1).
Why
1 is neither prime nor composite — a prime number must be greater than 1.
A prime number is a whole number greater than 1 whose only factors are 1 and itself. To check 1, test whether any prime up to √1 divides it evenly — if none do, it is prime.
Check another number
The prime factorization calculator tests any number and shows its prime factors and all divisors.
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Frequently asked questions
Is 1 a prime number?+
No, 1 is neither prime nor composite — a prime number must be greater than 1.
What is 1 divisible by?+
1 is divisible by more than just 1 and itself. Its prime factorization is 1 = 1.