66560009 has 2 divisors, whose sum is σ = 66560010. Its totient is φ = 66560008.

The previous prime is 66559991. The next prime is 66560023. The reversal of 66560009 is 90006566.

66560009 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., 45427600 + 21132409 = 6740^2 + 4597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66560009 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66560029) 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, 33280004 + 33280005.

It is an arithmetic number, because the mean of its divisors is an integer number (33280005).

Almost surely, 2^66560009 is an apocalyptic number.

It is an amenable number.

66560009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66560009 is an equidigital number, since it uses as much as digits as its factorization.

66560009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 66560009 is about 8158.4317733251. The cubic root of 66560009 is about 405.2637797942.

The spelling of 66560009 in words is "sixty-six million, five hundred sixty thousand, nine".