66065161 has 4 divisors (see below), whose sum is σ = 68343300. Its totient is φ = 63787024.

The previous prime is 66065107. The next prime is 66065173. The reversal of 66065161 is 16156066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16156066 = 2 ⋅8078033.

It can be written as a sum of positive squares in 2 ways, for example, as 17065161 + 49000000 = 4131^2 + 7000^2 .

It is a cyclic number.

It is not a de Polignac number, because 66065161 - 2¹⁹ = 65540873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66075161) 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 in 3 ways as a sum of consecutive naturals, for example, 1139026 + ... + 1139083.

It is an arithmetic number, because the mean of its divisors is an integer number (17085825).

Almost surely, 2^66065161 is an apocalyptic number.

It is an amenable number.

66065161 is a deficient number, since it is larger than the sum of its proper divisors (2278139).

66065161 is a wasteful number, since it uses less digits than its factorization.

66065161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278138.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 66065161 is about 8128.0477975957. The cubic root of 66065161 is about 404.2569538942.

The spelling of 66065161 in words is "sixty-six million, sixty-five thousand, one hundred sixty-one".