21311323023 has 16 divisors (see below), whose sum is σ = 29361678336. Its totient is φ = 13735194720.

The previous prime is 21311323013. The next prime is 21311323031. The reversal of 21311323023 is 32032311312.

It is a de Polignac number, because none of the positive numbers 2^k-21311323023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311323013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25140 + ... + 207977.

It is an arithmetic number, because the mean of its divisors is an integer number (1835104896).

Almost surely, 2^21311323023 is an apocalyptic number.

21311323023 is a deficient number, since it is larger than the sum of its proper divisors (8050355313).

21311323023 is a wasteful number, since it uses less digits than its factorization.

21311323023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234134.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21311323023 its reverse (32032311312), we get a palindrome (53343634335).

The spelling of 21311323023 in words is "twenty-one billion, three hundred eleven million, three hundred twenty-three thousand, twenty-three".