3959665 has 4 divisors (see below), whose sum is σ = 4751604. Its totient is φ = 3167728.

The previous prime is 3959663. The next prime is 3959677. The reversal of 3959665 is 5669593.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1140624 + 2819041 = 1068^2 + 1679^2 .

It is a cyclic number.

It is not a de Polignac number, because 3959665 - 2¹ = 3959663 is a prime.

It is a d-powerful number, because it can be written as 3⁸ + 9² + 5⁹ + 9² + 6² + 6⁶ + 5⁹ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3959663) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 395962 + ... + 395971.

It is an arithmetic number, because the mean of its divisors is an integer number (1187901).

Almost surely, 2^3959665 is an apocalyptic number.

It is an amenable number.

3959665 is a deficient number, since it is larger than the sum of its proper divisors (791939).

3959665 is an equidigital number, since it uses as much as digits as its factorization.

3959665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791938.

The product of its digits is 218700, while the sum is 43.

The square root of 3959665 is about 1989.8907005160. The cubic root of 3959665 is about 158.2047364572.

It can be divided in two parts, 3959 and 665, that added together give a square (4624 = 68²).

The spelling of 3959665 in words is "three million, nine hundred fifty-nine thousand, six hundred sixty-five".