21120011121 has 32 divisors (see below), whose sum is σ = 31102035840. Its totient is φ = 12641472000.

The previous prime is 21120011113. The next prime is 21120011153. The reversal of 21120011121 is 12111002112.

It is not a de Polignac number, because 21120011121 - 2³ = 21120011113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120011097 and 21120011106.

It is not an unprimeable number, because it can be changed into a prime (21120011161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1355451 + ... + 1370943.

It is an arithmetic number, because the mean of its divisors is an integer number (971938620).

Almost surely, 2^21120011121 is an apocalyptic number.

It is an amenable number.

21120011121 is a deficient number, since it is larger than the sum of its proper divisors (9982024719).

21120011121 is a wasteful number, since it uses less digits than its factorization.

21120011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16017.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21120011121 its reverse (12111002112), we get a palindrome (33231013233).

Subtracting from 21120011121 its reverse (12111002112), we obtain a palindrome (9009009009).

The spelling of 21120011121 in words is "twenty-one billion, one hundred twenty million, eleven thousand, one hundred twenty-one".