21121002111121 has 16 divisors (see below), whose sum is σ = 24254117314560. Its totient is φ = 18190085507280.

The previous prime is 21121002111109. The next prime is 21121002111149. The reversal of 21121002111121 is 12111120012112.

It is a cyclic number.

It is not a de Polignac number, because 21121002111121 - 2⁵ = 21121002111089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21121002111095 and 21121002111104.

It is not an unprimeable number, because it can be changed into a prime (21121002111151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15351280 + ... + 16670446.

It is an arithmetic number, because the mean of its divisors is an integer number (1515882332160).

Almost surely, 2^{21121002111121} is an apocalyptic number.

It is an amenable number.

21121002111121 is a deficient number, since it is larger than the sum of its proper divisors (3133115203439).

21121002111121 is a wasteful number, since it uses less digits than its factorization.

21121002111121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395804.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21121002111121 its reverse (12111120012112), we get a palindrome (33232122123233).

The spelling of 21121002111121 in words is "twenty-one trillion, one hundred twenty-one billion, two million, one hundred eleven thousand, one hundred twenty-one".