21323311111 has 4 divisors (see below), whose sum is σ = 21323840224. Its totient is φ = 21322782000.

The previous prime is 21323311103. The next prime is 21323311117. The reversal of 21323311111 is 11111332312.

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 21323311111 - 2³ = 21323311103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323311117) 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, 198630 + ... + 286531.

It is an arithmetic number, because the mean of its divisors is an integer number (5330960056).

Almost surely, 2^21323311111 is an apocalyptic number.

21323311111 is a deficient number, since it is larger than the sum of its proper divisors (529113).

21323311111 is an equidigital number, since it uses as much as digits as its factorization.

21323311111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529112.

The product of its digits is 108, while the sum is 19.

Adding to 21323311111 its reverse (11111332312), we get a palindrome (32434643423).

The spelling of 21323311111 in words is "twenty-one billion, three hundred twenty-three million, three hundred eleven thousand, one hundred eleven".