978809 has 16 divisors (see below), whose sum is σ = 1153152. Its totient is φ = 822528.

The previous prime is 978799. The next prime is 978821. The reversal of 978809 is 908879.

It is not a de Polignac number, because 978809 - 2¹² = 974713 is a prime.

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 978809.

It is not an unprimeable number, because it can be changed into a prime (978839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9452 + ... + 9554.

It is an arithmetic number, because the mean of its divisors is an integer number (72072).

2⁹⁷⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

978809 is a deficient number, since it is larger than the sum of its proper divisors (174343).

978809 is a wasteful number, since it uses less digits than its factorization.

978809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 978809 is about 989.3477649442. The cubic root of 978809 is about 99.2885842110.

The spelling of 978809 in words is "nine hundred seventy-eight thousand, eight hundred nine".