21233131111 has 4 divisors (see below), whose sum is σ = 21241437592. Its totient is φ = 21224824632.

The previous prime is 21233131097. The next prime is 21233131141. The reversal of 21233131111 is 11113133212.

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 21233131111 - 2¹⁵ = 21233098343 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 (21233131141) 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, 4149405 + ... + 4154518.

It is an arithmetic number, because the mean of its divisors is an integer number (5310359398).

Almost surely, 2^21233131111 is an apocalyptic number.

21233131111 is a deficient number, since it is larger than the sum of its proper divisors (8306481).

21233131111 is an equidigital number, since it uses as much as digits as its factorization.

21233131111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8306480.

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

Adding to 21233131111 its reverse (11113133212), we get a palindrome (32346264323).

The spelling of 21233131111 in words is "twenty-one billion, two hundred thirty-three million, one hundred thirty-one thousand, one hundred eleven".