6656809 has 8 divisors (see below), whose sum is σ = 7120008. Its totient is φ = 6201600.

The previous prime is 6656807. The next prime is 6656833. The reversal of 6656809 is 9086566.

It can be written as a sum of positive squares in 4 ways, for example, as 2795584 + 3861225 = 1672^2 + 1965^2 .

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

It is not a de Polignac number, because 6656809 - 2¹ = 6656807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6656807) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 222 + ... + 3655.

It is an arithmetic number, because the mean of its divisors is an integer number (890001).

Almost surely, 2^6656809 is an apocalyptic number.

It is an amenable number.

6656809 is a deficient number, since it is larger than the sum of its proper divisors (463199).

6656809 is a wasteful number, since it uses less digits than its factorization.

6656809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3995.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 6656809 is about 2580.0792623483. The cubic root of 6656809 is about 188.1143958217.

The spelling of 6656809 in words is "six million, six hundred fifty-six thousand, eight hundred nine".