840687 has 4 divisors (see below), whose sum is σ = 1120920. Its totient is φ = 560456.

The previous prime is 840683. The next prime is 840703. The reversal of 840687 is 786048.

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 840687 - 2² = 840683 is a prime.

It is an Ulam number.

It is a D-number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840687.

It is not an unprimeable number, because it can be changed into a prime (840683) 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, 140112 + ... + 140117.

It is an arithmetic number, because the mean of its divisors is an integer number (280230).

2⁸⁴⁰⁶⁸⁷ is an apocalyptic number.

840687 is a deficient number, since it is larger than the sum of its proper divisors (280233).

840687 is a wasteful number, since it uses less digits than its factorization.

840687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280232.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 840687 is about 916.8898516180. The cubic root of 840687 is about 94.3795952618.

The spelling of 840687 in words is "eight hundred forty thousand, six hundred eighty-seven".