21012211120 has 20 divisors (see below), whose sum is σ = 48853391040. Its totient is φ = 8404884416.

The previous prime is 21012211081. The next prime is 21012211127. The reversal of 21012211120 is 2111221012.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 21012211120.

It is not an unprimeable number, because it can be changed into a prime (21012211127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131326240 + ... + 131326399.

It is an arithmetic number, because the mean of its divisors is an integer number (2442669552).

Almost surely, 2^21012211120 is an apocalyptic number.

21012211120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012211120 is an abundant number, since it is smaller than the sum of its proper divisors (27841179920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012211120 is a wasteful number, since it uses less digits than its factorization.

21012211120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262652652 (or 262652646 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012211120 its reverse (2111221012), we get a palindrome (23123432132).

The spelling of 21012211120 in words is "twenty-one billion, twelve million, two hundred eleven thousand, one hundred twenty".