2121321213221 has 8 divisors (see below), whose sum is σ = 2424385854144. Its totient is φ = 1818261260640.

The previous prime is 2121321213211. The next prime is 2121321213227. The reversal of 2121321213221 is 1223121231212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121321213221 is a prime.

It is a super-2 number, since 2×2121321213221² (a number of 25 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 (2121321213227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 142175 + ... + 2064668.

It is an arithmetic number, because the mean of its divisors is an integer number (303048231768).

Almost surely, 2^{2121321213221} is an apocalyptic number.

It is an amenable number.

2121321213221 is a deficient number, since it is larger than the sum of its proper divisors (303064640923).

2121321213221 is a wasteful number, since it uses less digits than its factorization.

2121321213221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2344171.

The product of its digits is 576, while the sum is 23.

Adding to 2121321213221 its reverse (1223121231212), we get a palindrome (3344442444433).

The spelling of 2121321213221 in words is "two trillion, one hundred twenty-one billion, three hundred twenty-one million, two hundred thirteen thousand, two hundred twenty-one".