320591391 has 4 divisors (see below), whose sum is σ = 427455192. Its totient is φ = 213727592.

The previous prime is 320591387. The next prime is 320591393. The reversal of 320591391 is 193195023.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 320591391 - 2² = 320591387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320591393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53431896 + ... + 53431901.

It is an arithmetic number, because the mean of its divisors is an integer number (106863798).

Almost surely, 2^320591391 is an apocalyptic number.

320591391 is a deficient number, since it is larger than the sum of its proper divisors (106863801).

320591391 is a wasteful number, since it uses less digits than its factorization.

320591391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106863800.

The product of its (nonzero) digits is 7290, while the sum is 33.

The square root of 320591391 is about 17905.0660708080. The cubic root of 320591391 is about 684.4114795258.

The spelling of 320591391 in words is "three hundred twenty million, five hundred ninety-one thousand, three hundred ninety-one".