66487009 has 2 divisors, whose sum is σ = 66487010. Its totient is φ = 66487008.

The previous prime is 66486991. The next prime is 66487019. The reversal of 66487009 is 90078466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47651409 + 18835600 = 6903^2 + 4340^2 .

It is a cyclic number.

It is not a de Polignac number, because 66487009 - 2¹⁷ = 66355937 is a prime.

It is not a weakly prime, because it can be changed into another prime (66487019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33243504 + 33243505.

It is an arithmetic number, because the mean of its divisors is an integer number (33243505).

Almost surely, 2^66487009 is an apocalyptic number.

It is an amenable number.

66487009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66487009 is an equidigital number, since it uses as much as digits as its factorization.

66487009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 66487009 is about 8153.9566469291. The cubic root of 66487009 is about 405.1155672838.

The spelling of 66487009 in words is "sixty-six million, four hundred eighty-seven thousand, nine".