Is 15 a prime number?

No, 15 is not a prime number. It is a composite number: it ends in 5, so it is divisible by 5.

Why 15 is not prime

15 has divisors other than 1 and itself. The smallest is 3: 15 ÷ 3 = 5.

Prime factorization: 15 = 3 × 5.

Quick facts about 15

Even or odd: odd.
Nearest primes: 13 below and 17 above.
Primes up to 15: 6.

Is it prime? Nearby numbers

Number	Prime?
11	Yes
12	No, 2 × 2 × 3
13	Yes
14	No, 2 × 7
16	No, 2 × 2 × 2 × 2
17	Yes
18	No, 2 × 3 × 3
19	Yes

More about 15: factors of 15 · 15 squared · square root of 15 · 15 in binary · 15 in Roman numerals.

Another number? Use the prime number checker for any value, or see the list of prime numbers.