3876391665 has 12 divisors (see below), whose sum is σ = 6719078964. Its totient is φ = 2067408864.

The previous prime is 3876391639. The next prime is 3876391709. The reversal of 3876391665 is 5661936783.

3876391665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 2850598881 + 1025792784 = 53391^2 + 32028^2 .

It is not a de Polignac number, because 3876391665 - 2²¹ = 3874294513 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43070974 + ... + 43071063.

It is an arithmetic number, because the mean of its divisors is an integer number (559923247).

Almost surely, 2^3876391665 is an apocalyptic number.

It is an amenable number.

3876391665 is a deficient number, since it is larger than the sum of its proper divisors (2842687299).

3876391665 is a wasteful number, since it uses less digits than its factorization.

3876391665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86142048 (or 86142045 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 54.

The square root of 3876391665 is about 62260.6751087715. The cubic root of 3876391665 is about 1570.8783359271.

The spelling of 3876391665 in words is "three billion, eight hundred seventy-six million, three hundred ninety-one thousand, six hundred sixty-five".