664888618 has 16 divisors (see below), whose sum is σ = 1021892256. Its totient is φ = 324278640.

The previous prime is 664888613. The next prime is 664888619. The reversal of 664888618 is 816888466.

It is not an unprimeable number, because it can be changed into a prime (664888613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64980 + ... + 74512.

It is an arithmetic number, because the mean of its divisors is an integer number (63868266).

Almost surely, 2^664888618 is an apocalyptic number.

664888618 is a deficient number, since it is larger than the sum of its proper divisors (357003638).

664888618 is a wasteful number, since it uses less digits than its factorization.

664888618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10389.

The product of its digits is 3538944, while the sum is 55.

The square root of 664888618 is about 25785.4342216686. The cubic root of 664888618 is about 872.8031389744.

It can be divided in two parts, 6648 and 88618, that added together give a triangular number (95266 = T₄₃₆).

The spelling of 664888618 in words is "six hundred sixty-four million, eight hundred eighty-eight thousand, six hundred eighteen".