65666606609 has 2 divisors, whose sum is σ = 65666606610. Its totient is φ = 65666606608.

The previous prime is 65666606563. The next prime is 65666606611. The reversal of 65666606609 is 90660666656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58399555600 + 7267051009 = 241660^2 + 85247^2 .

It is a cyclic number.

It is not a de Polignac number, because 65666606609 - 2²⁰ = 65665558033 is a prime.

Together with 65666606611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (65666606699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32833303304 + 32833303305.

It is an arithmetic number, because the mean of its divisors is an integer number (32833303305).

Almost surely, 2^65666606609 is an apocalyptic number.

It is an amenable number.

65666606609 is a deficient number, since it is larger than the sum of its proper divisors (1).

65666606609 is an equidigital number, since it uses as much as digits as its factorization.

65666606609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12597120, while the sum is 56.

The spelling of 65666606609 in words is "sixty-five billion, six hundred sixty-six million, six hundred six thousand, six hundred nine".