641544664 has 16 divisors (see below), whose sum is σ = 1203183000. Its totient is φ = 320695872.

The previous prime is 641544647. The next prime is 641544697. The reversal of 641544664 is 466445146.

641544664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43287 + ... + 56185.

Almost surely, 2^641544664 is an apocalyptic number.

It is an amenable number.

641544664 is a deficient number, since it is larger than the sum of its proper divisors (561638336).

641544664 is a wasteful number, since it uses less digits than its factorization.

641544664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19122 (or 19118 counting only the distinct ones).

The product of its digits is 276480, while the sum is 40.

The square root of 641544664 is about 25328.7319856324. The cubic root of 641544664 is about 862.4666268400.

The spelling of 641544664 in words is "six hundred forty-one million, five hundred forty-four thousand, six hundred sixty-four".