656891 has 2 divisors, whose sum is σ = 656892. Its totient is φ = 656890.

The previous prime is 656839. The next prime is 656917. The reversal of 656891 is 198656.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 656891 - 2¹⁸ = 394747 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328445 + 328446.

It is an arithmetic number, because the mean of its divisors is an integer number (328446).

2⁶⁵⁶⁸⁹¹ is an apocalyptic number.

656891 is a deficient number, since it is larger than the sum of its proper divisors (1).

656891 is an equidigital number, since it uses as much as digits as its factorization.

656891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 35.

The square root of 656891 is about 810.4881245274. The cubic root of 656891 is about 86.9289506685.

The spelling of 656891 in words is "six hundred fifty-six thousand, eight hundred ninety-one".