664444172 has 24 divisors (see below), whose sum is σ = 1374713760. Its totient is φ = 274942080.

The previous prime is 664444169. The next prime is 664444177. The reversal of 664444172 is 271444466.

It is a happy number.

664444172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (664444177) 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, 408329 + ... + 409952.

It is an arithmetic number, because the mean of its divisors is an integer number (57279740).

Almost surely, 2^664444172 is an apocalyptic number.

It is an amenable number.

664444172 is an abundant number, since it is smaller than the sum of its proper divisors (710269588).

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

664444172 is a wasteful number, since it uses less digits than its factorization.

664444172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818321 (or 818319 counting only the distinct ones).

The product of its digits is 129024, while the sum is 38.

The square root of 664444172 is about 25776.8146208953. The cubic root of 664444172 is about 872.6086200131.

The spelling of 664444172 in words is "six hundred sixty-four million, four hundred forty-four thousand, one hundred seventy-two".