644896387239 has 16 divisors (see below), whose sum is σ = 943476865632. Its totient is φ = 389371402368.

The previous prime is 644896387229. The next prime is 644896387273. The reversal of 644896387239 is 932783698446.

644896387239 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644896387239 - 2⁷ = 644896387111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644896387229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155996092 + ... + 156000225.

It is an arithmetic number, because the mean of its divisors is an integer number (58967304102).

Almost surely, 2^644896387239 is an apocalyptic number.

644896387239 is a deficient number, since it is larger than the sum of its proper divisors (298580478393).

644896387239 is a wasteful number, since it uses less digits than its factorization.

644896387239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311996386.

The product of its digits is 376233984, while the sum is 69.

The spelling of 644896387239 in words is "six hundred forty-four billion, eight hundred ninety-six million, three hundred eighty-seven thousand, two hundred thirty-nine".