978664 has 16 divisors (see below), whose sum is σ = 1861920. Its totient is φ = 482160.

The previous prime is 978647. The next prime is 978683. The reversal of 978664 is 466879.

It is a nialpdrome in base 16.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 294 + ... + 1429.

It is an arithmetic number, because the mean of its divisors is an integer number (116370).

2⁹⁷⁸⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

978664 is a deficient number, since it is larger than the sum of its proper divisors (883256).

978664 is a wasteful number, since it uses less digits than its factorization.

978664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800 (or 1796 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 978664 is about 989.2744816278. The cubic root of 978664 is about 99.2836811244.

The spelling of 978664 in words is "nine hundred seventy-eight thousand, six hundred sixty-four".