3865665 has 8 divisors (see below), whose sum is σ = 6185088. Its totient is φ = 2061680.

The previous prime is 3865663. The next prime is 3865691. The reversal of 3865665 is 5665683.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3865665 - 2¹ = 3865663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3865663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128841 + ... + 128870.

It is an arithmetic number, because the mean of its divisors is an integer number (773136).

Almost surely, 2^3865665 is an apocalyptic number.

It is an amenable number.

3865665 is a deficient number, since it is larger than the sum of its proper divisors (2319423).

3865665 is a wasteful number, since it uses less digits than its factorization.

3865665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257719.

The product of its digits is 129600, while the sum is 39.

The square root of 3865665 is about 1966.1294463997. The cubic root of 3865665 is about 156.9428030795.

It can be divided in two parts, 38 and 65665, that added together give a triangular number (65703 = T₃₆₂).

The spelling of 3865665 in words is "three million, eight hundred sixty-five thousand, six hundred sixty-five".