809669661 has 8 divisors (see below), whose sum is σ = 1104665760. Its totient is φ = 527226672.

The previous prime is 809669639. The next prime is 809669669. The reversal of 809669661 is 166966908.

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

It is not a de Polignac number, because 809669661 - 2⁷ = 809669533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809669669) 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, 3138126 + ... + 3138383.

It is an arithmetic number, because the mean of its divisors is an integer number (138083220).

Almost surely, 2^809669661 is an apocalyptic number.

It is an amenable number.

809669661 is a deficient number, since it is larger than the sum of its proper divisors (294996099).

809669661 is a wasteful number, since it uses less digits than its factorization.

809669661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6276555.

The product of its (nonzero) digits is 839808, while the sum is 51.

The square root of 809669661 is about 28454.6948850273. The cubic root of 809669661 is about 932.0430135582.

The spelling of 809669661 in words is "eight hundred nine million, six hundred sixty-nine thousand, six hundred sixty-one".