231318431 has 4 divisors (see below), whose sum is σ = 231405864. Its totient is φ = 231231000.

The previous prime is 231318401. The next prime is 231318449. The reversal of 231318431 is 134813132.

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 231318431 - 2¹⁰ = 231317407 is a prime.

It is a super-2 number, since 2×231318431² = 107016433040603522, which contains 22 as substring.

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 231318431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231318401) 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, 39620 + ... + 45081.

It is an arithmetic number, because the mean of its divisors is an integer number (57851466).

Almost surely, 2^231318431 is an apocalyptic number.

231318431 is a deficient number, since it is larger than the sum of its proper divisors (87433).

231318431 is an equidigital number, since it uses as much as digits as its factorization.

231318431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87432.

The product of its digits is 1728, while the sum is 26.

The square root of 231318431 is about 15209.1561567366. The cubic root of 231318431 is about 613.8610519652.

The spelling of 231318431 in words is "two hundred thirty-one million, three hundred eighteen thousand, four hundred thirty-one".