840685 has 8 divisors (see below), whose sum is σ = 1013760. Its totient is φ = 669264.

The previous prime is 840683. The next prime is 840703. The reversal of 840685 is 586048.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 840685 - 2¹ = 840683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1696 + ... + 2134.

It is an arithmetic number, because the mean of its divisors is an integer number (126720).

2⁸⁴⁰⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

840685 is a deficient number, since it is larger than the sum of its proper divisors (173075).

840685 is a wasteful number, since it uses less digits than its factorization.

840685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 840685 is about 916.8887609738. Note that the first 3 decimals coincide. The cubic root of 840685 is about 94.3795204185.

The spelling of 840685 in words is "eight hundred forty thousand, six hundred eighty-five".