664640226 has 12 divisors (see below), whose sum is σ = 1440053862. Its totient is φ = 221546736.

The previous prime is 664640209. The next prime is 664640227. The reversal of 664640226 is 622046466.

664640226 is a `hidden beast` number, since 6 + 6 + 4 + 640 + 2 + 2 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 663320025 + 1320201 = 25755^2 + 1149^2 .

It is not an unprimeable number, because it can be changed into a prime (664640227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18462211 + ... + 18462246.

Almost surely, 2^664640226 is an apocalyptic number.

664640226 is an abundant number, since it is smaller than the sum of its proper divisors (775413636).

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

664640226 is a wasteful number, since it uses less digits than its factorization.

664640226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36924465 (or 36924462 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 664640226 is about 25780.6172540535. The cubic root of 664640226 is about 872.6944368979.

The spelling of 664640226 in words is "six hundred sixty-four million, six hundred forty thousand, two hundred twenty-six".