809799605 has 4 divisors (see below), whose sum is σ = 971759532. Its totient is φ = 647839680.

The previous prime is 809799593. The next prime is 809799673. The reversal of 809799605 is 506997908.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 370100644 + 439698961 = 19238^2 + 20969^2 .

It is not a de Polignac number, because 809799605 - 2¹² = 809795509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80979956 + ... + 80979965.

It is an arithmetic number, because the mean of its divisors is an integer number (242939883).

Almost surely, 2^809799605 is an apocalyptic number.

It is an amenable number.

809799605 is a deficient number, since it is larger than the sum of its proper divisors (161959927).

809799605 is a wasteful number, since it uses less digits than its factorization.

809799605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161959926.

The product of its (nonzero) digits is 1224720, while the sum is 53.

The square root of 809799605 is about 28456.9781424522. The cubic root of 809799605 is about 932.0928721300.

The spelling of 809799605 in words is "eight hundred nine million, seven hundred ninety-nine thousand, six hundred five".