21220120211221 has 8 divisors (see below), whose sum is σ = 22143734472384. Its totient is φ = 20296589311680.

The previous prime is 21220120211179. The next prime is 21220120211237. The reversal of 21220120211221 is 12211202102212.

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 21220120211221 - 2⁷ = 21220120211093 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 (21220120215221) 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, 20319940 + ... + 21338701.

It is an arithmetic number, because the mean of its divisors is an integer number (2767966809048).

Almost surely, 2^{21220120211221} is an apocalyptic number.

It is an amenable number.

21220120211221 is a deficient number, since it is larger than the sum of its proper divisors (923614261163).

21220120211221 is a wasteful number, since it uses less digits than its factorization.

21220120211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41680811.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21220120211221 its reverse (12211202102212), we get a palindrome (33431322313433).

The spelling of 21220120211221 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty million, two hundred eleven thousand, two hundred twenty-one".