21232323221 has 4 divisors (see below), whose sum is σ = 21313054752. Its totient is φ = 21151591692.

The previous prime is 21232323197. The next prime is 21232323223. The reversal of 21232323221 is 12232323212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21232323221 is a prime.

It is a super-2 number, since 2×21232323221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232323223) 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 3 ways as a sum of consecutive naturals, for example, 40365371 + ... + 40365896.

It is an arithmetic number, because the mean of its divisors is an integer number (5328263688).

Almost surely, 2^21232323221 is an apocalyptic number.

It is an amenable number.

21232323221 is a deficient number, since it is larger than the sum of its proper divisors (80731531).

21232323221 is an equidigital number, since it uses as much as digits as its factorization.

21232323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80731530.

The product of its digits is 1728, while the sum is 23.

Adding to 21232323221 its reverse (12232323212), we get a palindrome (33464646433).

Subtracting from 21232323221 its reverse (12232323212), we obtain a palindrome (9000000009).

The spelling of 21232323221 in words is "twenty-one billion, two hundred thirty-two million, three hundred twenty-three thousand, two hundred twenty-one".