644358161584 has 20 divisors (see below), whose sum is σ = 1256395815184. Its totient is φ = 320126983488.

The previous prime is 644358161581. The next prime is 644358161591. The reversal of 644358161584 is 485161853446.

It is not an unprimeable number, because it can be changed into a prime (644358161581) 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 3 ways as a sum of consecutive naturals, for example, 128253492 + ... + 128258515.

Almost surely, 2^644358161584 is an apocalyptic number.

It is an amenable number.

644358161584 is a deficient number, since it is larger than the sum of its proper divisors (612037653600).

644358161584 is a wasteful number, since it uses less digits than its factorization.

644358161584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256512172 (or 256512166 counting only the distinct ones).

The product of its digits is 11059200, while the sum is 55.

The spelling of 644358161584 in words is "six hundred forty-four billion, three hundred fifty-eight million, one hundred sixty-one thousand, five hundred eighty-four".