21312311223 has 24 divisors (see below), whose sum is σ = 33068850048. Its totient is φ = 12173666736.

The previous prime is 21312311201. The next prime is 21312311227. The reversal of 21312311223 is 32211321312.

It is not a de Polignac number, because 21312311223 - 2¹⁷ = 21312180151 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21312311223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312311227) 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 23 ways as a sum of consecutive naturals, for example, 364240 + ... + 418682.

It is an arithmetic number, because the mean of its divisors is an integer number (1377868752).

Almost surely, 2^21312311223 is an apocalyptic number.

21312311223 is a deficient number, since it is larger than the sum of its proper divisors (11756538825).

21312311223 is a wasteful number, since it uses less digits than its factorization.

21312311223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57123 (or 57116 counting only the distinct ones).

The product of its digits is 432, while the sum is 21.

Adding to 21312311223 its reverse (32211321312), we get a palindrome (53523632535).

The spelling of 21312311223 in words is "twenty-one billion, three hundred twelve million, three hundred eleven thousand, two hundred twenty-three".