66582161 has 2 divisors, whose sum is σ = 66582162. Its totient is φ = 66582160.

The previous prime is 66582157. The next prime is 66582169. The reversal of 66582161 is 16128566.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65691025 + 891136 = 8105^2 + 944^2 .

It is a cyclic number.

It is not a de Polignac number, because 66582161 - 2² = 66582157 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66582169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33291080 + 33291081.

It is an arithmetic number, because the mean of its divisors is an integer number (33291081).

Almost surely, 2^66582161 is an apocalyptic number.

It is an amenable number.

66582161 is a deficient number, since it is larger than the sum of its proper divisors (1).

66582161 is an equidigital number, since it uses as much as digits as its factorization.

66582161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 35.

The square root of 66582161 is about 8159.7892742399. The cubic root of 66582161 is about 405.3087337519.

The spelling of 66582161 in words is "sixty-six million, five hundred eighty-two thousand, one hundred sixty-one".