3991578816 has 56 divisors (see below), whose sum is σ = 10577413440. Its totient is φ = 1328465152.

The previous prime is 3991578803. The next prime is 3991578841. The reversal of 3991578816 is 6188751993.

3991578816 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110755 + ... + 142301.

Almost surely, 2^3991578816 is an apocalyptic number.

It is an amenable number.

3991578816 is an abundant number, since it is smaller than the sum of its proper divisors (6585834624).

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

3991578816 is a wasteful number, since it uses less digits than its factorization.

3991578816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32221 (or 32211 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 57.

The square root of 3991578816 is about 63178.9428211647. The cubic root of 3991578816 is about 1586.2862862695.

The spelling of 3991578816 in words is "three billion, nine hundred ninety-one million, five hundred seventy-eight thousand, eight hundred sixteen".