65566609 has 2 divisors, whose sum is σ = 65566610. Its totient is φ = 65566608.

The previous prime is 65566577. The next prime is 65566639. The reversal of 65566609 is 90666556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35283600 + 30283009 = 5940^2 + 5503^2 .

It is a cyclic number.

It is not a de Polignac number, because 65566609 - 2⁵ = 65566577 is a prime.

It is not a weakly prime, because it can be changed into another prime (65566639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32783304 + 32783305.

It is an arithmetic number, because the mean of its divisors is an integer number (32783305).

Almost surely, 2^65566609 is an apocalyptic number.

It is an amenable number.

65566609 is a deficient number, since it is larger than the sum of its proper divisors (1).

65566609 is an equidigital number, since it uses as much as digits as its factorization.

65566609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 291600, while the sum is 43.

The square root of 65566609 is about 8097.3211002158. The cubic root of 65566609 is about 403.2374946268.

The spelling of 65566609 in words is "sixty-five million, five hundred sixty-six thousand, six hundred nine".