231311213213 has 4 divisors (see below), whose sum is σ = 231318536988. Its totient is φ = 231303889440.

The previous prime is 231311213197. The next prime is 231311213219. The reversal of 231311213213 is 312312113132.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5551293049 + 225759920164 = 74507^2 + 475142^2 .

It is a cyclic number.

It is not a de Polignac number, because 231311213213 - 2⁴ = 231311213197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231311213219) 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, 3614306 + ... + 3677747.

It is an arithmetic number, because the mean of its divisors is an integer number (57829634247).

Almost surely, 2^231311213213 is an apocalyptic number.

It is an amenable number.

231311213213 is a deficient number, since it is larger than the sum of its proper divisors (7323775).

231311213213 is an equidigital number, since it uses as much as digits as its factorization.

231311213213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7323774.

The product of its digits is 648, while the sum is 23.

Adding to 231311213213 its reverse (312312113132), we get a palindrome (543623326345).

The spelling of 231311213213 in words is "two hundred thirty-one billion, three hundred eleven million, two hundred thirteen thousand, two hundred thirteen".