21121883072 has 56 divisors (see below), whose sum is σ = 42550384800. Its totient is φ = 10400956416.

The previous prime is 21121883071. The next prime is 21121883093. The reversal of 21121883072 is 27038812112.

It is a super-2 number, since 2×21121883072² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121883071) 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 7 ways as a sum of consecutive naturals, for example, 3589829 + ... + 3595707.

It is an arithmetic number, because the mean of its divisors is an integer number (759828300).

Almost surely, 2^21121883072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121883072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21275192400).

21121883072 is an abundant number, since it is smaller than the sum of its proper divisors (21428501728).

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

21121883072 is an equidigital number, since it uses as much as digits as its factorization.

21121883072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6733 (or 6723 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

The spelling of 21121883072 in words is "twenty-one billion, one hundred twenty-one million, eight hundred eighty-three thousand, seventy-two".