21003023321 has 12 divisors (see below), whose sum is σ = 25494354432. Its totient is φ = 17219869128.

The previous prime is 21003023297. The next prime is 21003023333. The reversal of 21003023321 is 12332030012.

It is not a de Polignac number, because 21003023321 - 2⁶ = 21003023257 is a prime.

It is a super-2 number, since 2×21003023321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21003023321.

It is not an unprimeable number, because it can be changed into a prime (21003023381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9316985 + ... + 9319238.

It is an arithmetic number, because the mean of its divisors is an integer number (2124529536).

Almost surely, 2^21003023321 is an apocalyptic number.

It is an amenable number.

21003023321 is a deficient number, since it is larger than the sum of its proper divisors (4491331111).

21003023321 is a wasteful number, since it uses less digits than its factorization.

21003023321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18636260 (or 18636253 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21003023321 its reverse (12332030012), we get a palindrome (33335053333).

The spelling of 21003023321 in words is "twenty-one billion, three million, twenty-three thousand, three hundred twenty-one".