231312211321 has 4 divisors (see below), whose sum is σ = 239288494500. Its totient is φ = 223335928144.

The previous prime is 231312211313. The next prime is 231312211327. The reversal of 231312211321 is 123112213132.

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 57580801600 + 173731409721 = 239960^2 + 416811^2 .

It is a cyclic number.

It is not a de Polignac number, because 231312211321 - 2³ = 231312211313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231312211292 and 231312211301.

It is not an unprimeable number, because it can be changed into a prime (231312211327) 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, 3988141546 + ... + 3988141603.

It is an arithmetic number, because the mean of its divisors is an integer number (59822123625).

Almost surely, 2^231312211321 is an apocalyptic number.

It is an amenable number.

231312211321 is a deficient number, since it is larger than the sum of its proper divisors (7976283179).

231312211321 is an equidigital number, since it uses as much as digits as its factorization.

231312211321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7976283178.

The product of its digits is 432, while the sum is 22.

Adding to 231312211321 its reverse (123112213132), we get a palindrome (354424424453).

The spelling of 231312211321 in words is "two hundred thirty-one billion, three hundred twelve million, two hundred eleven thousand, three hundred twenty-one".