656979 has 4 divisors (see below), whose sum is σ = 875976. Its totient is φ = 437984.

The previous prime is 656977. The next prime is 656989. The reversal of 656979 is 979656.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 656979 - 2¹ = 656977 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 656979.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 656979.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109494 + ... + 109499.

It is an arithmetic number, because the mean of its divisors is an integer number (218994).

2⁶⁵⁶⁹⁷⁹ is an apocalyptic number.

656979 is a deficient number, since it is larger than the sum of its proper divisors (218997).

656979 is a wasteful number, since it uses less digits than its factorization.

656979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218996.

The product of its digits is 102060, while the sum is 42.

The square root of 656979 is about 810.5424109817. The cubic root of 656979 is about 86.9328322897.

The spelling of 656979 in words is "six hundred fifty-six thousand, nine hundred seventy-nine".