3939865 has 4 divisors (see below), whose sum is σ = 4727844. Its totient is φ = 3151888.

The previous prime is 3939851. The next prime is 3939899. The reversal of 3939865 is 5689393.

3939865 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, and also an emirpimes, since its reverse is a distinct semiprime: 5689393 = 1151 ⋅4943.

It can be written as a sum of positive squares in 2 ways, for example, as 746496 + 3193369 = 864^2 + 1787^2 .

It is a cyclic number.

It is not a de Polignac number, because 3939865 - 2¹⁵ = 3907097 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 393982 + ... + 393991.

It is an arithmetic number, because the mean of its divisors is an integer number (1181961).

Almost surely, 2^3939865 is an apocalyptic number.

It is an amenable number.

3939865 is a deficient number, since it is larger than the sum of its proper divisors (787979).

3939865 is an equidigital number, since it uses as much as digits as its factorization.

3939865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 787978.

The product of its digits is 174960, while the sum is 43.

The square root of 3939865 is about 1984.9093178279. The cubic root of 3939865 is about 157.9405988317.

The spelling of 3939865 in words is "three million, nine hundred thirty-nine thousand, eight hundred sixty-five".