21211323221 has 8 divisors (see below), whose sum is σ = 23140806624. Its totient is φ = 19282036720.

The previous prime is 21211323193. The next prime is 21211323229. The reversal of 21211323221 is 12232311212.

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-21211323221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21211323193 and 21211323202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211323229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261131 + ... + 332583.

It is an arithmetic number, because the mean of its divisors is an integer number (2892600828).

Almost surely, 2^21211323221 is an apocalyptic number.

It is an amenable number.

21211323221 is a deficient number, since it is larger than the sum of its proper divisors (1929483403).

21211323221 is a wasteful number, since it uses less digits than its factorization.

21211323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98451.

The product of its digits is 288, while the sum is 20.

Adding to 21211323221 its reverse (12232311212), we get a palindrome (33443634433).

The spelling of 21211323221 in words is "twenty-one billion, two hundred eleven million, three hundred twenty-three thousand, two hundred twenty-one".