2111785728 has 144 divisors (see below), whose sum is σ = 6194791680. Its totient is φ = 634540032.

The previous prime is 2111785721. The next prime is 2111785757. The reversal of 2111785728 is 8275871112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2111785728.

It is not an unprimeable number, because it can be changed into a prime (2111785721) 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 15 ways as a sum of consecutive naturals, for example, 426853 + ... + 431771.

Almost surely, 2^2111785728 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 2111785728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3097395840).

2111785728 is an abundant number, since it is smaller than the sum of its proper divisors (4083005952).

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

2111785728 is a wasteful number, since it uses less digits than its factorization.

2111785728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4994 (or 4980 counting only the distinct ones).

The product of its digits is 62720, while the sum is 42.

The square root of 2111785728 is about 45954.1698652037. The cubic root of 2111785728 is about 1282.9703413392.

The spelling of 2111785728 in words is "two billion, one hundred eleven million, seven hundred eighty-five thousand, seven hundred twenty-eight".