3643865 has 16 divisors (see below), whose sum is σ = 4675968. Its totient is φ = 2716416.

The previous prime is 3643859. The next prime is 3643873. The reversal of 3643865 is 5683463.

It is a cyclic number.

It is not a de Polignac number, because 3643865 - 2⁸ = 3643609 is a prime.

It is a d-powerful number, because it can be written as 3⁵ + 6³ + 4⁶ + 3⁸ + 8 + 6⁸ + 5⁹ .

It is a Duffinian 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, 13724 + ... + 13986.

It is an arithmetic number, because the mean of its divisors is an integer number (292248).

Almost surely, 2^3643865 is an apocalyptic number.

It is an amenable number.

3643865 is a deficient number, since it is larger than the sum of its proper divisors (1032103).

3643865 is a wasteful number, since it uses less digits than its factorization.

3643865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448.

The product of its digits is 51840, while the sum is 35.

The square root of 3643865 is about 1908.8910393210. The cubic root of 3643865 is about 153.8818596932.

It can be divided in two parts, 3 and 643865, that multiplied together give a triangular number (1931595 = T₁₉₆₅).

The spelling of 3643865 in words is "three million, six hundred forty-three thousand, eight hundred sixty-five".