21323203221 has 16 divisors (see below), whose sum is σ = 29197196864. Its totient is φ = 13834727424.

The previous prime is 21323203219. The next prime is 21323203271. The reversal of 21323203221 is 12230232312.

It is a happy number.

It is not a de Polignac number, because 21323203221 - 2¹ = 21323203219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323203271) 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 15 ways as a sum of consecutive naturals, for example, 262636 + ... + 334101.

It is an arithmetic number, because the mean of its divisors is an integer number (1824824804).

Almost surely, 2^21323203221 is an apocalyptic number.

It is an amenable number.

21323203221 is a deficient number, since it is larger than the sum of its proper divisors (7873993643).

21323203221 is a wasteful number, since it uses less digits than its factorization.

21323203221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597060.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21323203221 its reverse (12230232312), we get a palindrome (33553435533).

The spelling of 21323203221 in words is "twenty-one billion, three hundred twenty-three million, two hundred three thousand, two hundred twenty-one".