21233322221 has 4 divisors (see below), whose sum is σ = 21234560412. Its totient is φ = 21232084032.

The previous prime is 21233322193. The next prime is 21233322223. The reversal of 21233322221 is 12222333212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13557109225 + 7676212996 = 116435^2 + 87614^2 .

It is a cyclic number.

It is not a de Polignac number, because 21233322221 - 2¹⁴ = 21233305837 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 (21233322223) 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 3 ways as a sum of consecutive naturals, for example, 593006 + ... + 627791.

It is an arithmetic number, because the mean of its divisors is an integer number (5308640103).

Almost surely, 2^21233322221 is an apocalyptic number.

It is an amenable number.

21233322221 is a deficient number, since it is larger than the sum of its proper divisors (1238191).

21233322221 is a wasteful number, since it uses less digits than its factorization.

21233322221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238190.

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

Adding to 21233322221 its reverse (12222333212), we get a palindrome (33455655433).

The spelling of 21233322221 in words is "twenty-one billion, two hundred thirty-three million, three hundred twenty-two thousand, two hundred twenty-one".