3991108784 has 80 divisors (see below), whose sum is σ = 8489289984. Its totient is φ = 1806624000.

The previous prime is 3991108663. The next prime is 3991108799. The reversal of 3991108784 is 4878011993.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2606099 + ... + 2607629.

Almost surely, 2^3991108784 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 3991108784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4244644992).

3991108784 is an abundant number, since it is smaller than the sum of its proper divisors (4498181200).

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

3991108784 is a wasteful number, since it uses less digits than its factorization.

3991108784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1786 (or 1780 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 50.

The square root of 3991108784 is about 63175.2228646643. Note that the first 3 decimals coincide. The cubic root of 3991108784 is about 1586.2240189631.

The spelling of 3991108784 in words is "three billion, nine hundred ninety-one million, one hundred eight thousand, seven hundred eighty-four".