644314387889 has 8 divisors (see below), whose sum is σ = 655021224768. Its totient is φ = 633612206160.

The previous prime is 644314387859. The next prime is 644314387903. The reversal of 644314387889 is 988783413446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644314387889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (644314387859) 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, 884117 + ... + 1438850.

It is an arithmetic number, because the mean of its divisors is an integer number (81877653096).

Almost surely, 2^644314387889 is an apocalyptic number.

It is an amenable number.

644314387889 is a deficient number, since it is larger than the sum of its proper divisors (10706836879).

644314387889 is a wasteful number, since it uses less digits than its factorization.

644314387889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2327575.

The product of its digits is 111476736, while the sum is 65.

The spelling of 644314387889 in words is "six hundred forty-four billion, three hundred fourteen million, three hundred eighty-seven thousand, eight hundred eighty-nine".