3878307991 has 4 divisors (see below), whose sum is σ = 3887979984. Its totient is φ = 3868636000.

The previous prime is 3878307941. The next prime is 3878307997. The reversal of 3878307991 is 1997038783.

3878307991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3878307991 - 2¹⁵ = 3878275223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3878307997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4835395 + ... + 4836196.

It is an arithmetic number, because the mean of its divisors is an integer number (971994996).

Almost surely, 2^3878307991 is an apocalyptic number.

3878307991 is a deficient number, since it is larger than the sum of its proper divisors (9671993).

3878307991 is an equidigital number, since it uses as much as digits as its factorization.

3878307991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9671992.

The product of its (nonzero) digits is 2286144, while the sum is 55.

The square root of 3878307991 is about 62276.0627448460. The cubic root of 3878307991 is about 1571.1371521438.

The spelling of 3878307991 in words is "three billion, eight hundred seventy-eight million, three hundred seven thousand, nine hundred ninety-one".