656809 has 2 divisors, whose sum is σ = 656810. Its totient is φ = 656808.

The previous prime is 656791. The next prime is 656819. The reversal of 656809 is 908656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 426409 + 230400 = 653^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 656809 - 2⁷ = 656681 is a prime.

It is not a weakly prime, because it can be changed into another prime (656819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328404 + 328405.

It is an arithmetic number, because the mean of its divisors is an integer number (328405).

2⁶⁵⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

656809 is a deficient number, since it is larger than the sum of its proper divisors (1).

656809 is an equidigital number, since it uses as much as digits as its factorization.

656809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 656809 is about 810.4375361495. The cubic root of 656809 is about 86.9253333912.

The spelling of 656809 in words is "six hundred fifty-six thousand, eight hundred nine".