21120136044 has 96 divisors (see below), whose sum is σ = 56954472960. Its totient is φ = 5966618112.

The previous prime is 21120136039. The next prime is 21120136057. The reversal of 21120136044 is 44063102112.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5006224 + ... + 5010440.

It is an arithmetic number, because the mean of its divisors is an integer number (593275760).

Almost surely, 2^21120136044 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 21120136044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28477236480).

21120136044 is an abundant number, since it is smaller than the sum of its proper divisors (35834336916).

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

21120136044 is a wasteful number, since it uses less digits than its factorization.

21120136044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4887 (or 4885 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

Adding to 21120136044 its reverse (44063102112), we get a palindrome (65183238156).

The spelling of 21120136044 in words is "twenty-one billion, one hundred twenty million, one hundred thirty-six thousand, forty-four".