664200644 has 12 divisors (see below), whose sum is σ = 1173860268. Its totient is φ = 328812000.

The previous prime is 664200643. The next prime is 664200673. The reversal of 664200644 is 446002466.

It can be written as a sum of positive squares in 2 ways, for example, as 343360900 + 320839744 = 18530^2 + 17912^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664200644.

It is not an unprimeable number, because it can be changed into a prime (664200643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821627 + ... + 822434.

It is an arithmetic number, because the mean of its divisors is an integer number (97821689).

Almost surely, 2^664200644 is an apocalyptic number.

It is an amenable number.

664200644 is a deficient number, since it is larger than the sum of its proper divisors (509659624).

664200644 is a wasteful number, since it uses less digits than its factorization.

664200644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644166 (or 1644164 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 664200644 is about 25772.0904080364. The cubic root of 664200644 is about 872.5019992675.

The spelling of 664200644 in words is "six hundred sixty-four million, two hundred thousand, six hundred forty-four".