66164009 has 2 divisors, whose sum is σ = 66164010. Its totient is φ = 66164008.

The previous prime is 66163997. The next prime is 66164011. The reversal of 66164009 is 90046166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61669609 + 4494400 = 7853^2 + 2120^2 .

It is a cyclic number.

It is not a de Polignac number, because 66164009 - 2⁸ = 66163753 is a prime.

It is a Sophie Germain prime.

Together with 66164011, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (66164069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33082004 + 33082005.

It is an arithmetic number, because the mean of its divisors is an integer number (33082005).

Almost surely, 2^66164009 is an apocalyptic number.

It is an amenable number.

66164009 is a deficient number, since it is larger than the sum of its proper divisors (1).

66164009 is an equidigital number, since it uses as much as digits as its factorization.

66164009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 66164009 is about 8134.1261976933. The cubic root of 66164009 is about 404.4584725044.

The spelling of 66164009 in words is "sixty-six million, one hundred sixty-four thousand, nine".