MathQuarryCalculators

Primes / Is 18 prime?

Is 18 a Prime Number?

No18 = 2 x 3^2

18 is NOT prime: 2 × 9 = 18. That makes 2 a genuine divisor of 18 beyond 1 and 18 itself. Fully broken down, 18 = 2 × 3^2, for 6 divisors total. 18 sits between primes 17 and 19, 1 below and 1 above. 18: 2, 3, 6, 9 divide 18 evenly, checked against 2-12. 18 is even, digit sum 9 for 18, digital root 9 for 18. 18 has 5 primes within 10 of 18.

Factors
1, 2, 3, 6, 9, 18
Number of factors
6
Prime?
No
Prime factorization
2 x 3^2
Even or odd
Even
Square
324
Cube
5832
Binary
10010
Hexadecimal
12
Roman numeral
XVIII
Perfect square?
No
Perfect cube?
No
Perfect number?
No
Triangular number?
No
Fibonacci number?
No
Full facts for 18 →Factors of 18 →