21323321221 has 16 divisors (see below), whose sum is σ = 22754971008. Its totient is φ = 19912000000.

The previous prime is 21323321219. The next prime is 21323321233. The reversal of 21323321221 is 12212332312.

It is a cyclic number.

It is not a de Polignac number, because 21323321221 - 2¹ = 21323321219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21323321192 and 21323321201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323321021) 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, 1112721 + ... + 1131721.

It is an arithmetic number, because the mean of its divisors is an integer number (1422185688).

Almost surely, 2^21323321221 is an apocalyptic number.

It is an amenable number.

21323321221 is a deficient number, since it is larger than the sum of its proper divisors (1431649787).

21323321221 is a wasteful number, since it uses less digits than its factorization.

21323321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19532.

The product of its digits is 864, while the sum is 22.

Adding to 21323321221 its reverse (12212332312), we get a palindrome (33535653533).

The spelling of 21323321221 in words is "twenty-one billion, three hundred twenty-three million, three hundred twenty-one thousand, two hundred twenty-one".