3978865 has 16 divisors (see below), whose sum is σ = 5285376. Its totient is φ = 2851200.

The previous prime is 3978859. The next prime is 3978883. The reversal of 3978865 is 5688793.

It is a de Polignac number, because none of the positive numbers 2^k-3978865 is a prime.

It is a Duffinian number.

Its product of digits (362880) is a multiple of the sum of its prime divisors (1080).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3520 + ... + 4510.

It is an arithmetic number, because the mean of its divisors is an integer number (330336).

Almost surely, 2^3978865 is an apocalyptic number.

It is an amenable number.

3978865 is a deficient number, since it is larger than the sum of its proper divisors (1306511).

3978865 is a wasteful number, since it uses less digits than its factorization.

3978865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its digits is 362880, while the sum is 46.

The square root of 3978865 is about 1994.7092519964. The cubic root of 3978865 is about 158.4600303239.

The spelling of 3978865 in words is "three million, nine hundred seventy-eight thousand, eight hundred sixty-five".