21330212221 has 8 divisors (see below), whose sum is σ = 21828514400. Its totient is φ = 20832012432.

The previous prime is 21330212209. The next prime is 21330212227. The reversal of 21330212221 is 12221203312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21330212221 - 2³¹ = 19182728573 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 (21330212227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 540055 + ... + 578203.

It is an arithmetic number, because the mean of its divisors is an integer number (2728564300).

Almost surely, 2^21330212221 is an apocalyptic number.

It is an amenable number.

21330212221 is a deficient number, since it is larger than the sum of its proper divisors (498302179).

21330212221 is a wasteful number, since it uses less digits than its factorization.

21330212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51195.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21330212221 its reverse (12221203312), we get a palindrome (33551415533).

The spelling of 21330212221 in words is "twenty-one billion, three hundred thirty million, two hundred twelve thousand, two hundred twenty-one".