66166717 has 4 divisors (see below), whose sum is σ = 66184380. Its totient is φ = 66149056.

The previous prime is 66166691. The next prime is 66166729. The reversal of 66166717 is 71766166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62821476 + 3345241 = 7926^2 + 1829^2 .

It is a cyclic number.

It is not a de Polignac number, because 66166717 - 2⁷ = 66166589 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66166717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66166747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 742 + ... + 11527.

It is an arithmetic number, because the mean of its divisors is an integer number (16546095).

Almost surely, 2^66166717 is an apocalyptic number.

It is an amenable number.

66166717 is a deficient number, since it is larger than the sum of its proper divisors (17663).

66166717 is a wasteful number, since it uses less digits than its factorization.

66166717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17662.

The product of its digits is 63504, while the sum is 40.

The square root of 66166717 is about 8134.2926551729. The cubic root of 66166717 is about 404.4639904016.

The spelling of 66166717 in words is "sixty-six million, one hundred sixty-six thousand, seven hundred seventeen".