644138097701 has 8 divisors (see below), whose sum is σ = 736163065920. Its totient is φ = 552114439488.

The previous prime is 644138097677. The next prime is 644138097731. The reversal of 644138097701 is 107790831446.

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

It is a cyclic number.

It is not a de Polignac number, because 644138097701 - 2¹⁰ = 644138096677 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644138097701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644138097731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1203005 + ... + 1653933.

It is an arithmetic number, because the mean of its divisors is an integer number (92020383240).

Almost surely, 2^644138097701 is an apocalyptic number.

It is an amenable number.

644138097701 is a deficient number, since it is larger than the sum of its proper divisors (92024968219).

644138097701 is a wasteful number, since it uses less digits than its factorization.

644138097701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655003.

The product of its (nonzero) digits is 1016064, while the sum is 50.

The spelling of 644138097701 in words is "six hundred forty-four billion, one hundred thirty-eight million, ninety-seven thousand, seven hundred one".