21120120122121 has 12 divisors (see below), whose sum is σ = 30516020731248. Its totient is φ = 14075842902264.

The previous prime is 21120120122093. The next prime is 21120120122147. The reversal of 21120120122121 is 12122102102112.

21120120122121 is a `hidden beast` number, since 21 + 1 + 201 + 201 + 221 + 21 = 666.

It is not a de Polignac number, because 21120120122121 - 2⁵ = 21120120122089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120120122094 and 21120120122103.

It is not an unprimeable number, because it can be changed into a prime (21120120162121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 353066695 + ... + 353126508.

It is an arithmetic number, because the mean of its divisors is an integer number (2543001727604).

Almost surely, 2^{21120120122121} is an apocalyptic number.

It is an amenable number.

21120120122121 is a deficient number, since it is larger than the sum of its proper divisors (9395900609127).

21120120122121 is a wasteful number, since it uses less digits than its factorization.

21120120122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706196532 (or 706196529 counting only the distinct ones).

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

Adding to 21120120122121 its reverse (12122102102112), we get a palindrome (33242222224233).

The spelling of 21120120122121 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty million, one hundred twenty-two thousand, one hundred twenty-one".