644626406513 has 8 divisors (see below), whose sum is σ = 652508871168. Its totient is φ = 636746701104.

The previous prime is 644626406471. The next prime is 644626406531. The reversal of 644626406513 is 315604626446.

644626406513 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 644626406513 - 2¹⁴ = 644626390129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644626406563) 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, 217745 + ... + 1156142.

It is an arithmetic number, because the mean of its divisors is an integer number (81563608896).

Almost surely, 2^644626406513 is an apocalyptic number.

It is an amenable number.

644626406513 is a deficient number, since it is larger than the sum of its proper divisors (7882464655).

644626406513 is a wasteful number, since it uses less digits than its factorization.

644626406513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1379623.

The product of its (nonzero) digits is 2488320, while the sum is 47.

The spelling of 644626406513 in words is "six hundred forty-four billion, six hundred twenty-six million, four hundred six thousand, five hundred thirteen".