66331009 has 2 divisors, whose sum is σ = 66331010. Its totient is φ = 66331008.

The previous prime is 66330997. The next prime is 66331019. The reversal of 66331009 is 90013366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65658609 + 672400 = 8103^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 66331009 - 2⁵ = 66330977 is a prime.

It is equal to p_3914623 and since 66331009 and 3914623 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66331019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33165504 + 33165505.

It is an arithmetic number, because the mean of its divisors is an integer number (33165505).

Almost surely, 2^66331009 is an apocalyptic number.

It is an amenable number.

66331009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66331009 is an equidigital number, since it uses as much as digits as its factorization.

66331009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 28.

The square root of 66331009 is about 8144.3851210512. The cubic root of 66331009 is about 404.7984751599.

The spelling of 66331009 in words is "sixty-six million, three hundred thirty-one thousand, nine".