21031311323 has 16 divisors (see below), whose sum is σ = 23781164544. Its totient is φ = 18433256160.

The previous prime is 21031311311. The next prime is 21031311331. The reversal of 21031311323 is 32311313012.

It is not a de Polignac number, because 21031311323 - 2²⁶ = 20964202459 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031311295 and 21031311304.

It is not an unprimeable number, because it can be changed into a prime (21031311373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 268940 + ... + 338217.

It is an arithmetic number, because the mean of its divisors is an integer number (1486322784).

Almost surely, 2^21031311323 is an apocalyptic number.

21031311323 is a deficient number, since it is larger than the sum of its proper divisors (2749853221).

21031311323 is a wasteful number, since it uses less digits than its factorization.

21031311323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607282.

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

Adding to 21031311323 its reverse (32311313012), we get a palindrome (53342624335).

The spelling of 21031311323 in words is "twenty-one billion, thirty-one million, three hundred eleven thousand, three hundred twenty-three".