21221211020121 has 32 divisors (see below), whose sum is σ = 36100377600000. Its totient is φ = 12068935154640.

The previous prime is 21221211020117. The next prime is 21221211020137. The reversal of 21221211020121 is 12102011212212.

21221211020121 is a `hidden beast` number, since 212 + 21 + 211 + 0 + 201 + 21 = 666.

It is not a de Polignac number, because 21221211020121 - 2² = 21221211020117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221211020094 and 21221211020103.

It is not an unprimeable number, because it can be changed into a prime (21221211020171) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 266030121 + ... + 266109878.

It is an arithmetic number, because the mean of its divisors is an integer number (1128136800000).

Almost surely, 2^{21221211020121} is an apocalyptic number.

21221211020121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221211020121 is a deficient number, since it is larger than the sum of its proper divisors (14879166579879).

21221211020121 is a wasteful number, since it uses less digits than its factorization.

21221211020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532140226 (or 532140220 counting only the distinct ones).

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

Adding to 21221211020121 its reverse (12102011212212), we get a palindrome (33323222232333).

The spelling of 21221211020121 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, twenty thousand, one hundred twenty-one".