21323044123 has 4 divisors (see below), whose sum is σ = 22010884288. Its totient is φ = 20635203960.

The previous prime is 21323044103. The next prime is 21323044151. The reversal of 21323044123 is 32144032312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21323044123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21323044103) 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, 343920036 + ... + 343920097.

It is an arithmetic number, because the mean of its divisors is an integer number (5502721072).

Almost surely, 2^21323044123 is an apocalyptic number.

21323044123 is a deficient number, since it is larger than the sum of its proper divisors (687840165).

21323044123 is an equidigital number, since it uses as much as digits as its factorization.

21323044123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687840164.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21323044123 its reverse (32144032312), we get a palindrome (53467076435).

The spelling of 21323044123 in words is "twenty-one billion, three hundred twenty-three million, forty-four thousand, one hundred twenty-three".