21221012220121 has 8 divisors (see below), whose sum is σ = 24257225303360. Its totient is φ = 18185959114128.

The previous prime is 21221012220113. The next prime is 21221012220131. The reversal of 21221012220121 is 12102221012212.

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 21221012220121 - 2³ = 21221012220113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221012220101) 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, 289955106 + ... + 290028283.

It is an arithmetic number, because the mean of its divisors is an integer number (3032153162920).

Almost surely, 2^{21221012220121} is an apocalyptic number.

It is an amenable number.

21221012220121 is a deficient number, since it is larger than the sum of its proper divisors (3036213083239).

21221012220121 is an equidigital number, since it uses as much as digits as its factorization.

21221012220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579988623.

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

Adding to 21221012220121 its reverse (12102221012212), we get a palindrome (33323233232333).

The spelling of 21221012220121 in words is "twenty-one trillion, two hundred twenty-one billion, twelve million, two hundred twenty thousand, one hundred twenty-one".