809399447 has 4 divisors (see below), whose sum is σ = 816825240. Its totient is φ = 801973656.

The previous prime is 809399443. The next prime is 809399471. The reversal of 809399447 is 744993908.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 809399447 - 2² = 809399443 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809399443) 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, 3712733 + ... + 3712950.

It is an arithmetic number, because the mean of its divisors is an integer number (204206310).

Almost surely, 2^809399447 is an apocalyptic number.

809399447 is a deficient number, since it is larger than the sum of its proper divisors (7425793).

809399447 is a wasteful number, since it uses less digits than its factorization.

809399447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7425792.

The product of its (nonzero) digits is 1959552, while the sum is 53.

The square root of 809399447 is about 28449.9463444134. The cubic root of 809399447 is about 931.9393173204.

The spelling of 809399447 in words is "eight hundred nine million, three hundred ninety-nine thousand, four hundred forty-seven".