66606161 has 2 divisors, whose sum is σ = 66606162. Its totient is φ = 66606160.

The previous prime is 66606157. The next prime is 66606209. The reversal of 66606161 is 16160666.

66606161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51051025 + 15555136 = 7145^2 + 3944^2 .

It is a cyclic number.

It is not a de Polignac number, because 66606161 - 2² = 66606157 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66606121) 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, 33303080 + 33303081.

It is an arithmetic number, because the mean of its divisors is an integer number (33303081).

Almost surely, 2^66606161 is an apocalyptic number.

It is an amenable number.

66606161 is a deficient number, since it is larger than the sum of its proper divisors (1).

66606161 is an equidigital number, since it uses as much as digits as its factorization.

66606161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 66606161 is about 8161.2597679525. The cubic root of 66606161 is about 405.3574266797.

It can be divided in two parts, 6660 and 6161, that added together give a palindrome (12821).

The spelling of 66606161 in words is "sixty-six million, six hundred six thousand, one hundred sixty-one".