21234031111 has 4 divisors (see below), whose sum is σ = 21727845832. Its totient is φ = 20740216392.

The previous prime is 21234031103. The next prime is 21234031163. The reversal of 21234031111 is 11113043212.

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 21234031111 - 2³ = 21234031103 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 (21234032111) 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, 246907296 + ... + 246907381.

It is an arithmetic number, because the mean of its divisors is an integer number (5431961458).

Almost surely, 2^21234031111 is an apocalyptic number.

21234031111 is a deficient number, since it is larger than the sum of its proper divisors (493814721).

21234031111 is an equidigital number, since it uses as much as digits as its factorization.

21234031111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493814720.

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

Adding to 21234031111 its reverse (11113043212), we get a palindrome (32347074323).

The spelling of 21234031111 in words is "twenty-one billion, two hundred thirty-four million, thirty-one thousand, one hundred eleven".