21123030323 has 4 divisors (see below), whose sum is σ = 21151848288. Its totient is φ = 21094212360.

The previous prime is 21123030277. The next prime is 21123030377. The reversal of 21123030323 is 32303032112.

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 21123030323 - 2²⁰ = 21121981747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123030295 and 21123030304.

It is not an unprimeable number, because it can be changed into a prime (21123030923) 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, 14407883 + ... + 14409348.

It is an arithmetic number, because the mean of its divisors is an integer number (5287962072).

Almost surely, 2^21123030323 is an apocalyptic number.

21123030323 is a deficient number, since it is larger than the sum of its proper divisors (28817965).

21123030323 is an equidigital number, since it uses as much as digits as its factorization.

21123030323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28817964.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21123030323 its reverse (32303032112), we get a palindrome (53426062435).

The spelling of 21123030323 in words is "twenty-one billion, one hundred twenty-three million, thirty thousand, three hundred twenty-three".