3855865 has 16 divisors (see below), whose sum is σ = 5030928. Its totient is φ = 2820096.

The previous prime is 3855857. The next prime is 3855913. The reversal of 3855865 is 5685583.

3855865 = 1388² + 1389².

It can be written as a sum of positive squares in 8 ways, for example, as 712336 + 3143529 = 844^2 + 1773^2 .

It is a cyclic number.

It is not a de Polignac number, because 3855865 - 2³ = 3855857 is a prime.

It is a Duffinian number.

3855865 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8689 + ... + 9121.

It is an arithmetic number, because the mean of its divisors is an integer number (314433).

Almost surely, 2^3855865 is an apocalyptic number.

3855865 is the 1389-th centered square number.

It is an amenable number.

3855865 is a deficient number, since it is larger than the sum of its proper divisors (1175063).

3855865 is a wasteful number, since it uses less digits than its factorization.

3855865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588.

The product of its digits is 144000, while the sum is 40.

The square root of 3855865 is about 1963.6356586699. The cubic root of 3855865 is about 156.8100668820.

The spelling of 3855865 in words is "three million, eight hundred fifty-five thousand, eight hundred sixty-five".