656815879 has 6 divisors (see below), whose sum is σ = 678150816. Its totient is φ = 635490180.

The previous prime is 656815849. The next prime is 656815889. The reversal of 656815879 is 978518656.

656815879 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 656815879 - 2¹⁷ = 656684807 is a prime.

It is a super-4 number, since 4×656815879⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656815849) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 140392 + ... + 144994.

It is an arithmetic number, because the mean of its divisors is an integer number (113025136).

Almost surely, 2^656815879 is an apocalyptic number.

656815879 is a deficient number, since it is larger than the sum of its proper divisors (21334937).

656815879 is an frugal number, since it uses more digits than its factorization.

656815879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9237 (or 4634 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 55.

The square root of 656815879 is about 25628.4193621066. The cubic root of 656815879 is about 869.2563685706.

The spelling of 656815879 in words is "six hundred fifty-six million, eight hundred fifteen thousand, eight hundred seventy-nine".