3656809 has 8 divisors (see below), whose sum is σ = 3977792. Its totient is φ = 3341520.

The previous prime is 3656801. The next prime is 3656827. The reversal of 3656809 is 9086563.

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

It is not a de Polignac number, because 3656809 - 2³ = 3656801 is a prime.

3656809 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3656801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27 + ... + 2704.

It is an arithmetic number, because the mean of its divisors is an integer number (497224).

Almost surely, 2^3656809 is an apocalyptic number.

It is an amenable number.

3656809 is a deficient number, since it is larger than the sum of its proper divisors (320983).

3656809 is a wasteful number, since it uses less digits than its factorization.

3656809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2847.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 3656809 is about 1912.2784839034. The cubic root of 3656809 is about 154.0638544441.

It can be divided in two parts, 3656 and 809, that added together give a triangular number (4465 = T₉₄).

The spelling of 3656809 in words is "three million, six hundred fifty-six thousand, eight hundred nine".