66195589 has 2 divisors, whose sum is σ = 66195590. Its totient is φ = 66195588.

The previous prime is 66195557. The next prime is 66195611. The reversal of 66195589 is 98559166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63473089 + 2722500 = 7967^2 + 1650^2 .

It is a cyclic number.

It is not a de Polignac number, because 66195589 - 2⁵ = 66195557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66195529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33097794 + 33097795.

It is an arithmetic number, because the mean of its divisors is an integer number (33097795).

Almost surely, 2^66195589 is an apocalyptic number.

It is an amenable number.

66195589 is a deficient number, since it is larger than the sum of its proper divisors (1).

66195589 is an equidigital number, since it uses as much as digits as its factorization.

66195589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 583200, while the sum is 49.

The square root of 66195589 is about 8136.0671703225. The cubic root of 66195589 is about 404.5228114461.

The spelling of 66195589 in words is "sixty-six million, one hundred ninety-five thousand, five hundred eighty-nine".