21221101022121 has 192 divisors, whose sum is σ = 42980250378240. Its totient is φ = 10172372273280.

The previous prime is 21221101022113. The next prime is 21221101022131. The reversal of 21221101022121 is 12122010112212.

21221101022121 is a `hidden beast` number, since 212 + 211 + 0 + 1 + 0 + 221 + 21 = 666.

It is not a de Polignac number, because 21221101022121 - 2³ = 21221101022113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221101022094 and 21221101022103.

It is not an unprimeable number, because it can be changed into a prime (21221101022101) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 583251496 + ... + 583287878.

It is an arithmetic number, because the mean of its divisors is an integer number (223855470720).

Almost surely, 2^{21221101022121} is an apocalyptic number.

21221101022121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221101022121 is an abundant number, since it is smaller than the sum of its proper divisors (21759149356119).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221101022121 is a wasteful number, since it uses less digits than its factorization.

21221101022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39513 (or 39500 counting only the distinct ones).

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

Adding to 21221101022121 its reverse (12122010112212), we get a palindrome (33343111134333).

Subtracting from 21221101022121 its reverse (12122010112212), we obtain a palindrome (9099090909909).

The spelling of 21221101022121 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred one million, twenty-two thousand, one hundred twenty-one".