320891 has 4 divisors (see below), whose sum is σ = 337800. Its totient is φ = 303984.

The previous prime is 320867. The next prime is 320899. The reversal of 320891 is 198023.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198023 = 7 ⋅28289.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320891 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 320891.

It is not an unprimeable number, because it can be changed into a prime (320899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8426 + ... + 8463.

It is an arithmetic number, because the mean of its divisors is an integer number (84450).

2³²⁰⁸⁹¹ is an apocalyptic number.

320891 is a deficient number, since it is larger than the sum of its proper divisors (16909).

320891 is a wasteful number, since it uses less digits than its factorization.

320891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16908.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 320891 is about 566.4724176869. The cubic root of 320891 is about 68.4624618950.

The spelling of 320891 in words is "three hundred twenty thousand, eight hundred ninety-one".