664036218 has 40 divisors (see below), whose sum is σ = 1575465012. Its totient is φ = 208324224.

The previous prime is 664036211. The next prime is 664036223. The reversal of 664036218 is 812630466.

664036218 is a `hidden beast` number, since 6 + 640 + 3 + 6 + 2 + 1 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 495374049 + 168662169 = 22257^2 + 12987^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (664036211) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 117805 + ... + 123312.

Almost surely, 2^664036218 is an apocalyptic number.

664036218 is an abundant number, since it is smaller than the sum of its proper divisors (911428794).

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

664036218 is a wasteful number, since it uses less digits than its factorization.

664036218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241148 (or 241139 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 664036218 is about 25768.9002093609. The cubic root of 664036218 is about 872.4299959981.

The spelling of 664036218 in words is "six hundred sixty-four million, thirty-six thousand, two hundred eighteen".