840659 has 4 divisors (see below), whose sum is σ = 844560. Its totient is φ = 836760.

The previous prime is 840643. The next prime is 840661. The reversal of 840659 is 956048.

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 840659 - 2⁴ = 840643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (840859) 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, 1607 + ... + 2064.

It is an arithmetic number, because the mean of its divisors is an integer number (211140).

2⁸⁴⁰⁶⁵⁹ is an apocalyptic number.

840659 is a deficient number, since it is larger than the sum of its proper divisors (3901).

840659 is a wasteful number, since it uses less digits than its factorization.

840659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3900.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 840659 is about 916.8745824812. The cubic root of 840659 is about 94.3785474450.

The spelling of 840659 in words is "eight hundred forty thousand, six hundred fifty-nine".