21120211121 has 4 divisors (see below), whose sum is σ = 22231801200. Its totient is φ = 20008621044.

The previous prime is 21120211093. The next prime is 21120211181. The reversal of 21120211121 is 12111202112.

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 21120211121 - 2¹⁸ = 21119948977 is a prime.

It is a super-2 number, since 2×21120211121² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120211096 and 21120211105.

It is not an unprimeable number, because it can be changed into a prime (21120211181) 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 3 ways as a sum of consecutive naturals, for example, 555795011 + ... + 555795048.

It is an arithmetic number, because the mean of its divisors is an integer number (5557950300).

Almost surely, 2^21120211121 is an apocalyptic number.

It is an amenable number.

21120211121 is a deficient number, since it is larger than the sum of its proper divisors (1111590079).

21120211121 is a wasteful number, since it uses less digits than its factorization.

21120211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111590078.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21120211121 its reverse (12111202112), we get a palindrome (33231413233).

Subtracting from 21120211121 its reverse (12111202112), we obtain a palindrome (9009009009).

The spelling of 21120211121 in words is "twenty-one billion, one hundred twenty million, two hundred eleven thousand, one hundred twenty-one".