66665171 has 8 divisors (see below), whose sum is σ = 69160080. Its totient is φ = 64183392.

The previous prime is 66665161. The next prime is 66665189. The reversal of 66665171 is 17156666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66665171 - 2⁶ = 66665107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66665101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7736 + ... + 13898.

It is an arithmetic number, because the mean of its divisors is an integer number (8645010).

Almost surely, 2^66665171 is an apocalyptic number.

66665171 is a deficient number, since it is larger than the sum of its proper divisors (2494909).

66665171 is a wasteful number, since it uses less digits than its factorization.

66665171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6565.

The product of its digits is 45360, while the sum is 38.

The square root of 66665171 is about 8164.8742182596. The cubic root of 66665171 is about 405.4771007000.

The spelling of 66665171 in words is "sixty-six million, six hundred sixty-five thousand, one hundred seventy-one".