8642809 has 4 divisors (see below), whose sum is σ = 9877504. Its totient is φ = 7408116.

The previous prime is 8642773. The next prime is 8642819. The reversal of 8642809 is 9082468.

8642809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8642809 - 2¹¹ = 8640761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8642819) 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, 617337 + ... + 617350.

It is an arithmetic number, because the mean of its divisors is an integer number (2469376).

Almost surely, 2^8642809 is an apocalyptic number.

It is an amenable number.

8642809 is a deficient number, since it is larger than the sum of its proper divisors (1234695).

8642809 is a wasteful number, since it uses less digits than its factorization.

8642809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234694.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 8642809 is about 2939.8654731127. The cubic root of 8642809 is about 205.2193487956.

The spelling of 8642809 in words is "eight million, six hundred forty-two thousand, eight hundred nine".