21211211323 has 4 divisors (see below), whose sum is σ = 21224298208. Its totient is φ = 21198124440.

The previous prime is 21211211311. The next prime is 21211211339. The reversal of 21211211323 is 32311211212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21211211323 - 2²⁹ = 20674340411 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21211211323.

It is not an unprimeable number, because it can be changed into a prime (21211211303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6541011 + ... + 6544252.

It is an arithmetic number, because the mean of its divisors is an integer number (5306074552).

Almost surely, 2^21211211323 is an apocalyptic number.

21211211323 is a deficient number, since it is larger than the sum of its proper divisors (13086885).

21211211323 is a wasteful number, since it uses less digits than its factorization.

21211211323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13086884.

The product of its digits is 144, while the sum is 19.

Adding to 21211211323 its reverse (32311211212), we get a palindrome (53522422535).

The spelling of 21211211323 in words is "twenty-one billion, two hundred eleven million, two hundred eleven thousand, three hundred twenty-three".