21120043676844 has 96 divisors (see below), whose sum is σ = 56950365136896. Its totient is φ = 5967019376640.

The previous prime is 21120043676839. The next prime is 21120043676863. The reversal of 21120043676844 is 44867634002112.

It is a junction number, because it is equal to n+sod(n) for n = 21120043676793 and 21120043676802.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1509804 + ... + 6672300.

It is an arithmetic number, because the mean of its divisors is an integer number (593232970176).

Almost surely, 2^{21120043676844} 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 21120043676844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28475182568448).

21120043676844 is an abundant number, since it is smaller than the sum of its proper divisors (35830321460052).

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

21120043676844 is a wasteful number, since it uses less digits than its factorization.

21120043676844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5163055 (or 5163053 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 48.

Adding to 21120043676844 its reverse (44867634002112), we get a palindrome (65987677678956).

The spelling of 21120043676844 in words is "twenty-one trillion, one hundred twenty billion, forty-three million, six hundred seventy-six thousand, eight hundred forty-four".