231213431 has 4 divisors (see below), whose sum is σ = 231808200. Its totient is φ = 230618664.

The previous prime is 231213397. The next prime is 231213439. The reversal of 231213431 is 134312132.

231213431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 231213431 - 2¹⁴ = 231197047 is a prime.

It is a super-2 number, since 2×231213431² = 106919301349583522, 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 (231213439) 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, 296801 + ... + 297578.

It is an arithmetic number, because the mean of its divisors is an integer number (57952050).

Almost surely, 2^231213431 is an apocalyptic number.

231213431 is a deficient number, since it is larger than the sum of its proper divisors (594769).

231213431 is an equidigital number, since it uses as much as digits as its factorization.

231213431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594768.

The product of its digits is 432, while the sum is 20.

The square root of 231213431 is about 15205.7038968934. The cubic root of 231213431 is about 613.7681566936.

Adding to 231213431 its reverse (134312132), we get a palindrome (365525563).

The spelling of 231213431 in words is "two hundred thirty-one million, two hundred thirteen thousand, four hundred thirty-one".