21221101202121 has 96 divisors (see below), whose sum is σ = 33839597226240. Its totient is φ = 12758533337088.

The previous prime is 21221101202089. The next prime is 21221101202219. The reversal of 21221101202121 is 12120210112212.

21221101202121 is a `hidden beast` number, since 21 + 221 + 101 + 202 + 121 = 666.

It is not a de Polignac number, because 21221101202121 - 2⁵ = 21221101202089 is a prime.

It is a super-2 number, since 2×21221101202121² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21221101202094 and 21221101202103.

It is not an unprimeable number, because it can be changed into a prime (21221101272121) 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 95 ways as a sum of consecutive naturals, for example, 2533253685 + ... + 2533262061.

It is an arithmetic number, because the mean of its divisors is an integer number (352495804440).

Almost surely, 2^{21221101202121} is an apocalyptic number.

It is an amenable number.

21221101202121 is a deficient number, since it is larger than the sum of its proper divisors (12618496024119).

21221101202121 is a wasteful number, since it uses less digits than its factorization.

21221101202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15183 (or 15180 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21221101202121 its reverse (12120210112212), we get a palindrome (33341311314333).

The spelling of 21221101202121 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred one million, two hundred two thousand, one hundred twenty-one".