31311023321 has 4 divisors (see below), whose sum is σ = 31314336000. Its totient is φ = 31307710644.

The previous prime is 31311023287. The next prime is 31311023323. The reversal of 31311023321 is 12332011313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12332011313 = 19 ⋅649053227.

It is a cyclic number.

It is not a de Polignac number, because 31311023321 - 2⁶ = 31311023257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31311023293 and 31311023302.

It is not an unprimeable number, because it can be changed into a prime (31311023323) 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, 1642121 + ... + 1661078.

It is an arithmetic number, because the mean of its divisors is an integer number (7828584000).

Almost surely, 2^31311023321 is an apocalyptic number.

It is an amenable number.

31311023321 is a deficient number, since it is larger than the sum of its proper divisors (3312679).

31311023321 is an equidigital number, since it uses as much as digits as its factorization.

31311023321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3312678.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31311023321 its reverse (12332011313), we get a palindrome (43643034634).

The spelling of 31311023321 in words is "thirty-one billion, three hundred eleven million, twenty-three thousand, three hundred twenty-one".