320391 has 12 divisors (see below), whose sum is σ = 468832. Its totient is φ = 210816.

The previous prime is 320389. The next prime is 320401. The reversal of 320391 is 193023.

It is not a de Polignac number, because 320391 - 2¹ = 320389 is a prime.

It is a Duffinian number.

320391 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 320391.

It is not an unprimeable number, because it can be changed into a prime (320291) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 690 + ... + 1056.

2³²⁰³⁹¹ is an apocalyptic number.

320391 is a deficient number, since it is larger than the sum of its proper divisors (148441).

320391 is a wasteful number, since it uses less digits than its factorization.

320391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 467 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

The square root of 320391 is about 566.0309178835. The cubic root of 320391 is about 68.4268848864.

The spelling of 320391 in words is "three hundred twenty thousand, three hundred ninety-one".