66165689 has 2 divisors, whose sum is σ = 66165690. Its totient is φ = 66165688.

The previous prime is 66165679. The next prime is 66165703. The reversal of 66165689 is 98656166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50523664 + 15642025 = 7108^2 + 3955^2 .

It is a cyclic number.

It is not a de Polignac number, because 66165689 - 2²⁰ = 65117113 is a prime.

It is a super-3 number, since 3×66165689³ (a number of 24 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (66165629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33082844 + 33082845.

It is an arithmetic number, because the mean of its divisors is an integer number (33082845).

Almost surely, 2^66165689 is an apocalyptic number.

It is an amenable number.

66165689 is a deficient number, since it is larger than the sum of its proper divisors (1).

66165689 is an equidigital number, since it uses as much as digits as its factorization.

66165689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 47.

The square root of 66165689 is about 8134.2294656593. The cubic root of 66165689 is about 404.4618957375.

The spelling of 66165689 in words is "sixty-six million, one hundred sixty-five thousand, six hundred eighty-nine".