391328943 has 16 divisors (see below), whose sum is σ = 528659040. Its totient is φ = 257458176.

The previous prime is 391328911. The next prime is 391328947. The reversal of 391328943 is 349823193.

It is not a de Polignac number, because 391328943 - 2⁵ = 391328911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 391328895 and 391328904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391328947) 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 15 ways as a sum of consecutive naturals, for example, 111471 + ... + 114927.

It is an arithmetic number, because the mean of its divisors is an integer number (33041190).

Almost surely, 2^391328943 is an apocalyptic number.

391328943 is a deficient number, since it is larger than the sum of its proper divisors (137330097).

391328943 is a wasteful number, since it uses less digits than its factorization.

391328943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3946.

The product of its digits is 139968, while the sum is 42.

The square root of 391328943 is about 19782.0358659062. The cubic root of 391328943 is about 731.4432839640.

The spelling of 391328943 in words is "three hundred ninety-one million, three hundred twenty-eight thousand, nine hundred forty-three".