66604609 has 2 divisors, whose sum is σ = 66604610. Its totient is φ = 66604608.

The previous prime is 66604591. The next prime is 66604613. The reversal of 66604609 is 90640666.

66604609 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., 66064384 + 540225 = 8128^2 + 735^2 .

It is a cyclic number.

It is not a de Polignac number, because 66604609 - 2¹⁹ = 66080321 is a prime.

It is not a weakly prime, because it can be changed into another prime (66604649) 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, 33302304 + 33302305.

It is an arithmetic number, because the mean of its divisors is an integer number (33302305).

Almost surely, 2^66604609 is an apocalyptic number.

It is an amenable number.

66604609 is a deficient number, since it is larger than the sum of its proper divisors (1).

66604609 is an equidigital number, since it uses as much as digits as its factorization.

66604609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 66604609 is about 8161.1646840387. The cubic root of 66604609 is about 405.3542782242.

The spelling of 66604609 in words is "sixty-six million, six hundred four thousand, six hundred nine".