840978 has 24 divisors (see below), whose sum is σ = 1918800. Its totient is φ = 265464.

The previous prime is 840967. The next prime is 840979. The reversal of 840978 is 879048.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (840979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 888 + ... + 1571.

It is an arithmetic number, because the mean of its divisors is an integer number (79950).

2⁸⁴⁰⁹⁷⁸ is an apocalyptic number.

840978 is an abundant number, since it is smaller than the sum of its proper divisors (1077822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

840978 is a wasteful number, since it uses less digits than its factorization.

840978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2486 (or 2483 counting only the distinct ones).

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

The square root of 840978 is about 917.0485265241. The cubic root of 840978 is about 94.3904836955.

The spelling of 840978 in words is "eight hundred forty thousand, nine hundred seventy-eight".