840609 has 24 divisors (see below), whose sum is σ = 1515072. Its totient is φ = 436320.

The previous prime is 840601. The next prime is 840611. The reversal of 840609 is 906048.

840609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 840609 - 2³ = 840601 is a prime.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840609.

It is not an unprimeable number, because it can be changed into a prime (840601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87 + ... + 1299.

It is an arithmetic number, because the mean of its divisors is an integer number (63128).

2⁸⁴⁰⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

840609 is a deficient number, since it is larger than the sum of its proper divisors (674463).

840609 is a wasteful number, since it uses less digits than its factorization.

840609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237 (or 1234 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 840609 is about 916.8473155330. The cubic root of 840609 is about 94.3766762856.

The spelling of 840609 in words is "eight hundred forty thousand, six hundred nine".