21312011121 has 16 divisors (see below), whose sum is σ = 30090538368. Its totient is φ = 13370912000.

The previous prime is 21312011089. The next prime is 21312011159. The reversal of 21312011121 is 12111021312.

It is a cyclic number.

It is not a de Polignac number, because 21312011121 - 2⁵ = 21312011089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21312011121.

It is not an unprimeable number, because it can be changed into a prime (21312011321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 855796 + ... + 880346.

It is an arithmetic number, because the mean of its divisors is an integer number (1880658648).

Almost surely, 2^21312011121 is an apocalyptic number.

It is an amenable number.

21312011121 is a deficient number, since it is larger than the sum of its proper divisors (8778527247).

21312011121 is a wasteful number, since it uses less digits than its factorization.

21312011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41592.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21312011121 its reverse (12111021312), we get a palindrome (33423032433).

The spelling of 21312011121 in words is "twenty-one billion, three hundred twelve million, eleven thousand, one hundred twenty-one".