65688709 has 2 divisors, whose sum is σ = 65688710. Its totient is φ = 65688708.

The previous prime is 65688673. The next prime is 65688739. The reversal of 65688709 is 90788656.

65688709 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., 48233025 + 17455684 = 6945^2 + 4178^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65688709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65688739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32844354 + 32844355.

It is an arithmetic number, because the mean of its divisors is an integer number (32844355).

Almost surely, 2^65688709 is an apocalyptic number.

It is an amenable number.

65688709 is a deficient number, since it is larger than the sum of its proper divisors (1).

65688709 is an equidigital number, since it uses as much as digits as its factorization.

65688709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 49.

The square root of 65688709 is about 8104.8571239720. The cubic root of 65688709 is about 403.4876461799.

The spelling of 65688709 in words is "sixty-five million, six hundred eighty-eight thousand, seven hundred nine".