66339209 has 2 divisors, whose sum is σ = 66339210. Its totient is φ = 66339208.

The previous prime is 66339193. The next prime is 66339227. The reversal of 66339209 is 90293366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64850809 + 1488400 = 8053^2 + 1220^2 .

It is a cyclic number.

It is not a de Polignac number, because 66339209 - 2⁴ = 66339193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66339289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33169604 + 33169605.

It is an arithmetic number, because the mean of its divisors is an integer number (33169605).

Almost surely, 2^66339209 is an apocalyptic number.

It is an amenable number.

66339209 is a deficient number, since it is larger than the sum of its proper divisors (1).

66339209 is an equidigital number, since it uses as much as digits as its factorization.

66339209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 38.

The square root of 66339209 is about 8144.8885198019. Note that the first 3 decimals coincide. The cubic root of 66339209 is about 404.8151551952.

The spelling of 66339209 in words is "sixty-six million, three hundred thirty-nine thousand, two hundred nine".