666945618 has 8 divisors (see below), whose sum is σ = 1333891248. Its totient is φ = 222315204.

The previous prime is 666945611. The next prime is 666945623. The reversal of 666945618 is 816549666.

It is a happy number.

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

666945618 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (666945611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55578796 + ... + 55578807.

It is an arithmetic number, because the mean of its divisors is an integer number (166736406).

Almost surely, 2^666945618 is an apocalyptic number.

666945618 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666945618 is a wasteful number, since it uses less digits than its factorization.

666945618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111157608.

The product of its digits is 1866240, while the sum is 51.

The square root of 666945618 is about 25825.2902791043. The cubic root of 666945618 is about 873.7022909638.

The spelling of 666945618 in words is "six hundred sixty-six million, nine hundred forty-five thousand, six hundred eighteen".