644401164433013 has 8 divisors (see below), whose sum is σ = 694086011824128. Its totient is φ = 594732820906224.

The previous prime is 644401164432967. The next prime is 644401164433043. The reversal of 644401164433013 is 310334461104446.

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

It is not a de Polignac number, because 644401164433013 - 2¹⁰ = 644401164431989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644401164433043) 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, 4125884981 + ... + 4126041162.

It is an arithmetic number, because the mean of its divisors is an integer number (86760751478016).

Almost surely, 2^{644401164433013} is an apocalyptic number.

It is an amenable number.

644401164433013 is a deficient number, since it is larger than the sum of its proper divisors (49684847391115).

644401164433013 is a wasteful number, since it uses less digits than its factorization.

644401164433013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8251932163.

The product of its (nonzero) digits is 995328, while the sum is 44.

The spelling of 644401164433013 in words is "six hundred forty-four trillion, four hundred one billion, one hundred sixty-four million, four hundred thirty-three thousand, thirteen".