21311243234221 has 8 divisors (see below), whose sum is σ = 21402996189120. Its totient is φ = 21219492744672.

The previous prime is 21311243234167. The next prime is 21311243234251. The reversal of 21311243234221 is 12243234211312.

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-21311243234221 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 (21311243234251) 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, 17904766 + ... + 19057888.

It is an arithmetic number, because the mean of its divisors is an integer number (2675374523640).

Almost surely, 2^{21311243234221} is an apocalyptic number.

It is an amenable number.

21311243234221 is a deficient number, since it is larger than the sum of its proper divisors (91752954899).

21311243234221 is a wasteful number, since it uses less digits than its factorization.

21311243234221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232675.

The product of its digits is 13824, while the sum is 31.

Adding to 21311243234221 its reverse (12243234211312), we get a palindrome (33554477445533).

The spelling of 21311243234221 in words is "twenty-one trillion, three hundred eleven billion, two hundred forty-three million, two hundred thirty-four thousand, two hundred twenty-one".