21330001332221 has 4 divisors (see below), whose sum is σ = 21330020983932. Its totient is φ = 21329981680512.

The previous prime is 21330001332203. The next prime is 21330001332293. The reversal of 21330001332221 is 12223310003312.

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 3832002002500 + 17497999329721 = 1957550^2 + 4183061^2 .

It is a cyclic number.

It is not a de Polignac number, because 21330001332221 - 2³⁸ = 21055123425277 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 (21330001332421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8096270 + ... + 10402383.

It is an arithmetic number, because the mean of its divisors is an integer number (5332505245983).

Almost surely, 2^{21330001332221} is an apocalyptic number.

It is an amenable number.

21330001332221 is a deficient number, since it is larger than the sum of its proper divisors (19651711).

21330001332221 is a wasteful number, since it uses less digits than its factorization.

21330001332221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19651710.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 21330001332221 its reverse (12223310003312), we get a palindrome (33553311335533).

The spelling of 21330001332221 in words is "twenty-one trillion, three hundred thirty billion, one million, three hundred thirty-two thousand, two hundred twenty-one".