21120243072 has 32 divisors (see below), whose sum is σ = 56100646680. Its totient is φ = 7040080896.

The previous prime is 21120243059. The next prime is 21120243091. The reversal of 21120243072 is 27034202112.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

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, 27499933 + ... + 27500700.

Almost surely, 2^21120243072 is an apocalyptic number.

It is an amenable number.

21120243072 is an abundant number, since it is smaller than the sum of its proper divisors (34980403608).

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

21120243072 is an equidigital number, since it uses as much as digits as its factorization.

21120243072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55000650 (or 55000638 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

Adding to 21120243072 its reverse (27034202112), we get a palindrome (48154445184).

The spelling of 21120243072 in words is "twenty-one billion, one hundred twenty million, two hundred forty-three thousand, seventy-two".