66668171 has 6 divisors (see below), whose sum is σ = 67861980. Its totient is φ = 65476548.

The previous prime is 66668167. The next prime is 66668177. The reversal of 66668171 is 17186666.

It is not a de Polignac number, because 66668171 - 2² = 66668167 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66668177) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62186 + ... + 63248.

It is an arithmetic number, because the mean of its divisors is an integer number (11310330).

Almost surely, 2^66668171 is an apocalyptic number.

66668171 is a deficient number, since it is larger than the sum of its proper divisors (1193809).

66668171 is an frugal number, since it uses more digits than its factorization.

66668171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185 (or 1122 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 66668171 is about 8165.0579299843. The cubic root of 66668171 is about 405.4831829017.

The spelling of 66668171 in words is "sixty-six million, six hundred sixty-eight thousand, one hundred seventy-one".