3959865 has 48 divisors (see below), whose sum is σ = 8456448. Its totient is φ = 1669248.

The previous prime is 3959849. The next prime is 3959869. The reversal of 3959865 is 5689593.

3959865 is nontrivially palindromic in base 8 and base 14.

It is not a de Polignac number, because 3959865 - 2⁴ = 3959849 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 3959865.

It is not an unprimeable number, because it can be changed into a prime (3959869) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3612 + ... + 4578.

It is an arithmetic number, because the mean of its divisors is an integer number (176176).

Almost surely, 2^3959865 is an apocalyptic number.

3959865 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

3959865 is an abundant number, since it is smaller than the sum of its proper divisors (4496583).

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

3959865 is a wasteful number, since it uses less digits than its factorization.

3959865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998 (or 995 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 3959865 is about 1989.9409538979. The cubic root of 3959865 is about 158.2074000171.

The spelling of 3959865 in words is "three million, nine hundred fifty-nine thousand, eight hundred sixty-five".