MathQuarryCalculators

Primes / Is 391 prime?

Is 391 a Prime Number?

No391 = 17 x 23

391 is NOT prime: 17 × 23 = 391. That makes 17 a genuine divisor of 391 beyond 1 and 391 itself. Fully broken down, 391 = 17 × 23, for 4 divisors total. 391 sits between primes 389 and 397, 2 below and 6 above. 391 shares no factor with 2-12; 391's divisors start beyond that range. 391 is odd, digit sum 13 for 391, digital root 4 for 391. 391 has 4 primes within 10 of 391.

Factors
1, 17, 23, 391
Number of factors
4
Prime?
No
Prime factorization
17 x 23
Even or odd
Odd
Square
152881
Cube
59776471
Binary
110000111
Hexadecimal
187
Roman numeral
CCCXCI
Perfect square?
No
Perfect cube?
No
Perfect number?
No
Triangular number?
No
Fibonacci number?
No
Full facts for 391 →Factors of 391 →