21331111123 has 16 divisors (see below), whose sum is σ = 24982130880. Its totient is φ = 17831347200.

The previous prime is 21331111091. The next prime is 21331111141. The reversal of 21331111123 is 32111113312.

It is a cyclic number.

It is not a de Polignac number, because 21331111123 - 2⁵ = 21331111091 is a prime.

It is a super-2 number, since 2×21331111123² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21331111123.

It is not an unprimeable number, because it can be changed into a prime (21331111723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 874513 + ... + 898573.

It is an arithmetic number, because the mean of its divisors is an integer number (1561383180).

Almost surely, 2^21331111123 is an apocalyptic number.

21331111123 is a deficient number, since it is larger than the sum of its proper divisors (3651019757).

21331111123 is a wasteful number, since it uses less digits than its factorization.

21331111123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27198.

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

Adding to 21331111123 its reverse (32111113312), we get a palindrome (53442224435).

The spelling of 21331111123 in words is "twenty-one billion, three hundred thirty-one million, one hundred eleven thousand, one hundred twenty-three".