66075661 has 2 divisors, whose sum is σ = 66075662. Its totient is φ = 66075660.

The previous prime is 66075629. The next prime is 66075677. The reversal of 66075661 is 16657066.

It is a happy number.

66075661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34928100 + 31147561 = 5910^2 + 5581^2 .

It is a cyclic number.

It is not a de Polignac number, because 66075661 - 2⁵ = 66075629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66075661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66075161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33037830 + 33037831.

It is an arithmetic number, because the mean of its divisors is an integer number (33037831).

Almost surely, 2^66075661 is an apocalyptic number.

It is an amenable number.

66075661 is a deficient number, since it is larger than the sum of its proper divisors (1).

66075661 is an equidigital number, since it uses as much as digits as its factorization.

66075661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 66075661 is about 8128.6936834894. The cubic root of 66075661 is about 404.2783694839.

The spelling of 66075661 in words is "sixty-six million, seventy-five thousand, six hundred sixty-one".