21002323023 has 24 divisors (see below), whose sum is σ = 33132018816. Its totient is φ = 12714277200.

The previous prime is 21002323009. The next prime is 21002323033. The reversal of 21002323023 is 32032320012.

It is a happy number.

It is not a de Polignac number, because 21002323023 - 2¹³ = 21002314831 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002322987 and 21002323005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002323033) 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 23 ways as a sum of consecutive naturals, for example, 31773 + ... + 207398.

It is an arithmetic number, because the mean of its divisors is an integer number (1380500784).

Almost surely, 2^21002323023 is an apocalyptic number.

21002323023 is a deficient number, since it is larger than the sum of its proper divisors (12129695793).

21002323023 is a wasteful number, since it uses less digits than its factorization.

21002323023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240075 (or 240072 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

Adding to 21002323023 its reverse (32032320012), we get a palindrome (53034643035).

The spelling of 21002323023 in words is "twenty-one billion, two million, three hundred twenty-three thousand, twenty-three".