3685809 has 4 divisors (see below), whose sum is σ = 4914416. Its totient is φ = 2457204.

The previous prime is 3685783. The next prime is 3685811. The reversal of 3685809 is 9085863.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9085863 = 3 ⋅3028621.

It is a de Polignac number, because none of the positive numbers 2^k-3685809 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3685849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 614299 + ... + 614304.

It is an arithmetic number, because the mean of its divisors is an integer number (1228604).

Almost surely, 2^3685809 is an apocalyptic number.

It is an amenable number.

3685809 is a deficient number, since it is larger than the sum of its proper divisors (1228607).

3685809 is a wasteful number, since it uses less digits than its factorization.

3685809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228606.

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 3685809 is about 1919.8460875810. The cubic root of 3685809 is about 154.4700458262.

The spelling of 3685809 in words is "three million, six hundred eighty-five thousand, eight hundred nine".