656978 has 16 divisors (see below), whose sum is σ = 1137024. Its totient is φ = 278880.

The previous prime is 656977. The next prime is 656989. The reversal of 656978 is 879656.

It is a happy number.

It is a Curzon 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 656978.

It is not an unprimeable number, because it can be changed into a prime (656977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2198 + ... + 2478.

It is an arithmetic number, because the mean of its divisors is an integer number (71064).

2⁶⁵⁶⁹⁷⁸ is an apocalyptic number.

656978 is a deficient number, since it is larger than the sum of its proper divisors (480046).

656978 is a wasteful number, since it uses less digits than its factorization.

656978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457.

The product of its digits is 90720, while the sum is 41.

The square root of 656978 is about 810.5417941106. The cubic root of 656978 is about 86.9327881823.

The spelling of 656978 in words is "six hundred fifty-six thousand, nine hundred seventy-eight".