391168231 has 4 divisors (see below), whose sum is σ = 391527864. Its totient is φ = 390808600.

The previous prime is 391168213. The next prime is 391168243. The reversal of 391168231 is 132861193.

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 391168231 - 2¹⁷ = 391037159 is a prime.

It is a super-2 number, since 2×391168231² = 306025169887338722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391168201) 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, 178180 + ... + 180361.

It is an arithmetic number, because the mean of its divisors is an integer number (97881966).

Almost surely, 2^391168231 is an apocalyptic number.

391168231 is a deficient number, since it is larger than the sum of its proper divisors (359633).

391168231 is a wasteful number, since it uses less digits than its factorization.

391168231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359632.

The product of its digits is 7776, while the sum is 34.

The square root of 391168231 is about 19777.9733794947. The cubic root of 391168231 is about 731.3431399028.

The spelling of 391168231 in words is "three hundred ninety-one million, one hundred sixty-eight thousand, two hundred thirty-one".