21121011021121 has 4 divisors (see below), whose sum is σ = 23041102932144. Its totient is φ = 19200919110100.

The previous prime is 21121011021113. The next prime is 21121011021127. The reversal of 21121011021121 is 12112011012112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21121011021121 - 2³ = 21121011021113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21121011021095 and 21121011021104.

It is not an unprimeable number, because it can be changed into a prime (21121011021127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 960045955495 + ... + 960045955516.

It is an arithmetic number, because the mean of its divisors is an integer number (5760275733036).

Almost surely, 2^{21121011021121} is an apocalyptic number.

It is an amenable number.

21121011021121 is a deficient number, since it is larger than the sum of its proper divisors (1920091911023).

21121011021121 is a wasteful number, since it uses less digits than its factorization.

21121011021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1920091911022.

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

Adding to 21121011021121 its reverse (12112011012112), we get a palindrome (33233022033233).

Subtracting from 21121011021121 its reverse (12112011012112), we obtain a palindrome (9009000009009).

The spelling of 21121011021121 in words is "twenty-one trillion, one hundred twenty-one billion, eleven million, twenty-one thousand, one hundred twenty-one".