21321021023 has 16 divisors (see below), whose sum is σ = 22030348032. Its totient is φ = 20621496000.

The previous prime is 21321021011. The next prime is 21321021061. The reversal of 21321021023 is 32012012312.

It is a cyclic number.

It is not a de Polignac number, because 21321021023 - 2⁸ = 21321020767 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21321020992 and 21321021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321021083) 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, 2270528 + ... + 2279898.

It is an arithmetic number, because the mean of its divisors is an integer number (1376896752).

Almost surely, 2^21321021023 is an apocalyptic number.

21321021023 is a deficient number, since it is larger than the sum of its proper divisors (709327009).

21321021023 is a wasteful number, since it uses less digits than its factorization.

21321021023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9886.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21321021023 its reverse (32012012312), we get a palindrome (53333033335).

The spelling of 21321021023 in words is "twenty-one billion, three hundred twenty-one million, twenty-one thousand, twenty-three".