66589709 has 2 divisors, whose sum is σ = 66589710. Its totient is φ = 66589708.

The previous prime is 66589703. The next prime is 66589763. The reversal of 66589709 is 90798566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63648484 + 2941225 = 7978^2 + 1715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66589709 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66589703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33294854 + 33294855.

It is an arithmetic number, because the mean of its divisors is an integer number (33294855).

Almost surely, 2^66589709 is an apocalyptic number.

It is an amenable number.

66589709 is a deficient number, since it is larger than the sum of its proper divisors (1).

66589709 is an equidigital number, since it uses as much as digits as its factorization.

66589709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 66589709 is about 8160.2517730766. The cubic root of 66589709 is about 405.3240489389.

The spelling of 66589709 in words is "sixty-six million, five hundred eighty-nine thousand, seven hundred nine".