656861 has 8 divisors (see below), whose sum is σ = 692664. Its totient is φ = 622080.

The previous prime is 656839. The next prime is 656891. The reversal of 656861 is 168656.

656861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8836 + 648025 = 94^2 + 805^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 656861 - 2¹⁴ = 640477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1301 + ... + 1733.

It is an arithmetic number, because the mean of its divisors is an integer number (86583).

2⁶⁵⁶⁸⁶¹ is an apocalyptic number.

It is an amenable number.

656861 is a deficient number, since it is larger than the sum of its proper divisors (35803).

656861 is a wasteful number, since it uses less digits than its factorization.

656861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511.

The product of its digits is 8640, while the sum is 32.

The square root of 656861 is about 810.4696169506. The cubic root of 656861 is about 86.9276273093.

The spelling of 656861 in words is "six hundred fifty-six thousand, eight hundred sixty-one".