21123323113 has 4 divisors (see below), whose sum is σ = 21332465028. Its totient is φ = 20914181200.

The previous prime is 21123323077. The next prime is 21123323153. The reversal of 21123323113 is 31132332112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17122507609 + 4000815504 = 130853^2 + 63252^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123323113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123323153) 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, 104570806 + ... + 104571007.

It is an arithmetic number, because the mean of its divisors is an integer number (5333116257).

Almost surely, 2^21123323113 is an apocalyptic number.

It is an amenable number.

21123323113 is a deficient number, since it is larger than the sum of its proper divisors (209141915).

21123323113 is a wasteful number, since it uses less digits than its factorization.

21123323113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209141914.

The product of its digits is 648, while the sum is 22.

Adding to 21123323113 its reverse (31132332112), we get a palindrome (52255655225).

The spelling of 21123323113 in words is "twenty-one billion, one hundred twenty-three million, three hundred twenty-three thousand, one hundred thirteen".