21233312221 has 4 divisors (see below), whose sum is σ = 23163613344. Its totient is φ = 19303011100.

The previous prime is 21233312209. The next prime is 21233312263. The reversal of 21233312221 is 12221333212.

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 not a de Polignac number, because 21233312221 - 2⁵ = 21233312189 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21233312192 and 21233312201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233313221) 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, 965150545 + ... + 965150566.

It is an arithmetic number, because the mean of its divisors is an integer number (5790903336).

Almost surely, 2^21233312221 is an apocalyptic number.

It is an amenable number.

21233312221 is a deficient number, since it is larger than the sum of its proper divisors (1930301123).

21233312221 is a wasteful number, since it uses less digits than its factorization.

21233312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930301122.

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

Adding to 21233312221 its reverse (12221333212), we get a palindrome (33454645433).

The spelling of 21233312221 in words is "twenty-one billion, two hundred thirty-three million, three hundred twelve thousand, two hundred twenty-one".