66171217166 has 64 divisors (see below), whose sum is σ = 107547181056. Its totient is φ = 30456096000.

The previous prime is 66171217109. The next prime is 66171217181.

66171217166 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 72955685 + ... + 72956591.

It is an arithmetic number, because the mean of its divisors is an integer number (1680424704).

Almost surely, 2^66171217166 is an apocalyptic number.

66171217166 is a deficient number, since it is larger than the sum of its proper divisors (41375963890).

66171217166 is a wasteful number, since it uses less digits than its factorization.

66171217166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1457.

The product of its digits is 127008, while the sum is 44.

The spelling of 66171217166 in words is "sixty-six billion, one hundred seventy-one million, two hundred seventeen thousand, one hundred sixty-six".