656718989 has 2 divisors, whose sum is σ = 656718990. Its totient is φ = 656718988.

The previous prime is 656718967. The next prime is 656719009. The reversal of 656718989 is 989817656.

656718989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 458388100 + 198330889 = 21410^2 + 14083^2 .

It is a cyclic number.

It is not a de Polignac number, because 656718989 - 2¹⁶ = 656653453 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656718089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328359494 + 328359495.

It is an arithmetic number, because the mean of its divisors is an integer number (328359495).

Almost surely, 2^656718989 is an apocalyptic number.

It is an amenable number.

656718989 is a deficient number, since it is larger than the sum of its proper divisors (1).

656718989 is an equidigital number, since it uses as much as digits as its factorization.

656718989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6531840, while the sum is 59.

The square root of 656718989 is about 25626.5290080416. The cubic root of 656718989 is about 869.2136237701.

The spelling of 656718989 in words is "six hundred fifty-six million, seven hundred eighteen thousand, nine hundred eighty-nine".