840987 has 18 divisors (see below), whose sum is σ = 1413828. Its totient is φ = 480312.

The previous prime is 840979. The next prime is 840989. The reversal of 840987 is 789048.

It is not a de Polignac number, because 840987 - 2³ = 840979 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840987.

It is not an unprimeable number, because it can be changed into a prime (840989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 513 + ... + 1394.

It is an arithmetic number, because the mean of its divisors is an integer number (78546).

2⁸⁴⁰⁹⁸⁷ is an apocalyptic number.

840987 is a deficient number, since it is larger than the sum of its proper divisors (572841).

840987 is a wasteful number, since it uses less digits than its factorization.

840987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1927 (or 1917 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 840987 is about 917.0534335577. The cubic root of 840987 is about 94.3908204111.

The spelling of 840987 in words is "eight hundred forty thousand, nine hundred eighty-seven".