66731009 has 2 divisors, whose sum is σ = 66731010. Its totient is φ = 66731008.

The previous prime is 66730997. The next prime is 66731039. The reversal of 66731009 is 90013766.

66731009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43930384 + 22800625 = 6628^2 + 4775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66731009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66731039) 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, 33365504 + 33365505.

It is an arithmetic number, because the mean of its divisors is an integer number (33365505).

Almost surely, 2^66731009 is an apocalyptic number.

It is an amenable number.

66731009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66731009 is an equidigital number, since it uses as much as digits as its factorization.

66731009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 32.

The square root of 66731009 is about 8168.9050061804. The cubic root of 66731009 is about 405.6105387836.

The spelling of 66731009 in words is "sixty-six million, seven hundred thirty-one thousand, nine".