664857618 has 8 divisors (see below), whose sum is σ = 1329715248. Its totient is φ = 221619204.

The previous prime is 664857617. The next prime is 664857623. The reversal of 664857618 is 816758466.

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

664857618 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (664857617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55404796 + ... + 55404807.

It is an arithmetic number, because the mean of its divisors is an integer number (166214406).

Almost surely, 2^664857618 is an apocalyptic number.

664857618 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.

664857618 is a wasteful number, since it uses less digits than its factorization.

664857618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110809608.

The product of its digits is 1935360, while the sum is 51.

The square root of 664857618 is about 25784.8331000998. The cubic root of 664857618 is about 872.7895741371.

The spelling of 664857618 in words is "six hundred sixty-four million, eight hundred fifty-seven thousand, six hundred eighteen".