11781112728 has 144 divisors (see below), whose sum is σ = 37659678840. Its totient is φ = 3059992320.

The previous prime is 11781112723. The next prime is 11781112747. The reversal of 11781112728 is 82721118711.

It is a happy number.

11781112728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11781112723) 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 35 ways as a sum of consecutive naturals, for example, 100900 + ... + 183692.

Almost surely, 2^11781112728 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 11781112728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18829839420).

11781112728 is an abundant number, since it is smaller than the sum of its proper divisors (25878566112).

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

11781112728 is a wasteful number, since it uses less digits than its factorization.

11781112728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82838 (or 82816 counting only the distinct ones).

The product of its digits is 12544, while the sum is 39.

The spelling of 11781112728 in words is "eleven billion, seven hundred eighty-one million, one hundred twelve thousand, seven hundred twenty-eight".