21323212111 has 4 divisors (see below), whose sum is σ = 21326288472. Its totient is φ = 21320135752.

The previous prime is 21323212103. The next prime is 21323212153. The reversal of 21323212111 is 11121232312.

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 21323212111 - 2³ = 21323212103 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 (21323212411) 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, 1527760 + ... + 1541653.

It is an arithmetic number, because the mean of its divisors is an integer number (5331572118).

Almost surely, 2^21323212111 is an apocalyptic number.

21323212111 is a deficient number, since it is larger than the sum of its proper divisors (3076361).

21323212111 is an equidigital number, since it uses as much as digits as its factorization.

21323212111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3076360.

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

Adding to 21323212111 its reverse (11121232312), we get a palindrome (32444444423).

The spelling of 21323212111 in words is "twenty-one billion, three hundred twenty-three million, two hundred twelve thousand, one hundred eleven".