644813310165 has 8 divisors (see below), whose sum is σ = 1031701296288. Its totient is φ = 343900432080.

The previous prime is 644813310149. The next prime is 644813310227. The reversal of 644813310165 is 561013318446.

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

It is not a de Polignac number, because 644813310165 - 2⁴ = 644813310149 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21493776991 + ... + 21493777020.

It is an arithmetic number, because the mean of its divisors is an integer number (128962662036).

Almost surely, 2^644813310165 is an apocalyptic number.

It is an amenable number.

644813310165 is a deficient number, since it is larger than the sum of its proper divisors (386887986123).

644813310165 is a wasteful number, since it uses less digits than its factorization.

644813310165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42987554019.

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 644813310165 in words is "six hundred forty-four billion, eight hundred thirteen million, three hundred ten thousand, one hundred sixty-five".