3661865 has 4 divisors (see below), whose sum is σ = 4394244. Its totient is φ = 2929488.

The previous prime is 3661841. The next prime is 3661871. The reversal of 3661865 is 5681663.

3661865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2343961 + 1317904 = 1531^2 + 1148^2 .

It is a cyclic number.

It is not a de Polignac number, because 3661865 - 2¹² = 3657769 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 366182 + ... + 366191.

It is an arithmetic number, because the mean of its divisors is an integer number (1098561).

Almost surely, 2^3661865 is an apocalyptic number.

It is an amenable number.

3661865 is a deficient number, since it is larger than the sum of its proper divisors (732379).

3661865 is an equidigital number, since it uses as much as digits as its factorization.

3661865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732378.

The product of its digits is 25920, while the sum is 35.

The square root of 3661865 is about 1913.6000104515. The cubic root of 3661865 is about 154.1348259866.

The spelling of 3661865 in words is "three million, six hundred sixty-one thousand, eight hundred sixty-five".