231340391 has 4 divisors (see below), whose sum is σ = 237592872. Its totient is φ = 225087912.

The previous prime is 231340309. The next prime is 231340393. The reversal of 231340391 is 193043132.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231340391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231340391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231340393) 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, 3126185 + ... + 3126258.

It is an arithmetic number, because the mean of its divisors is an integer number (59398218).

Almost surely, 2^231340391 is an apocalyptic number.

231340391 is a deficient number, since it is larger than the sum of its proper divisors (6252481).

231340391 is an equidigital number, since it uses as much as digits as its factorization.

231340391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6252480.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 231340391 is about 15209.8780731471. The cubic root of 231340391 is about 613.8804767931.

The spelling of 231340391 in words is "two hundred thirty-one million, three hundred forty thousand, three hundred ninety-one".