21113130121 has 4 divisors (see below), whose sum is σ = 21117427200. Its totient is φ = 21108833044.

The previous prime is 21113130089. The next prime is 21113130131. The reversal of 21113130121 is 12103131112.

It is a happy number.

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 21113130121 - 2⁵ = 21113130089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21113130095 and 21113130104.

It is not an unprimeable number, because it can be changed into a prime (21113130131) 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, 2141161 + ... + 2150998.

It is an arithmetic number, because the mean of its divisors is an integer number (5279356800).

Almost surely, 2^21113130121 is an apocalyptic number.

It is an amenable number.

21113130121 is a deficient number, since it is larger than the sum of its proper divisors (4297079).

21113130121 is an equidigital number, since it uses as much as digits as its factorization.

21113130121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4297078.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21113130121 its reverse (12103131112), we get a palindrome (33216261233).

Subtracting from 21113130121 its reverse (12103131112), we obtain a palindrome (9009999009).

The spelling of 21113130121 in words is "twenty-one billion, one hundred thirteen million, one hundred thirty thousand, one hundred twenty-one".