66238309 has 2 divisors, whose sum is σ = 66238310. Its totient is φ = 66238308.

The previous prime is 66238279. The next prime is 66238327. The reversal of 66238309 is 90383266.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35402500 + 30835809 = 5950^2 + 5553^2 .

It is a cyclic number.

It is not a de Polignac number, because 66238309 - 2¹⁵ = 66205541 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 (66230309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33119154 + 33119155.

It is an arithmetic number, because the mean of its divisors is an integer number (33119155).

Almost surely, 2^66238309 is an apocalyptic number.

It is an amenable number.

66238309 is a deficient number, since it is larger than the sum of its proper divisors (1).

66238309 is an equidigital number, since it uses as much as digits as its factorization.

66238309 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 66238309 is about 8138.6920939424. The cubic root of 66238309 is about 404.6098137099.

The spelling of 66238309 in words is "sixty-six million, two hundred thirty-eight thousand, three hundred nine".