644767646325 has 24 divisors (see below), whose sum is σ = 1162926374496. Its totient is φ = 312614616000.

The previous prime is 644767646293. The next prime is 644767646333. The reversal of 644767646325 is 523646767446.

It is not a de Polignac number, because 644767646325 - 2⁵ = 644767646293 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 23 ways as a sum of consecutive naturals, for example, 390767446 + ... + 390769095.

It is an arithmetic number, because the mean of its divisors is an integer number (48455265604).

Almost surely, 2^644767646325 is an apocalyptic number.

It is an amenable number.

644767646325 is a deficient number, since it is larger than the sum of its proper divisors (518158728171).

644767646325 is a wasteful number, since it uses less digits than its factorization.

644767646325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781536565 (or 781536560 counting only the distinct ones).

The product of its digits is 121927680, while the sum is 60.

The spelling of 644767646325 in words is "six hundred forty-four billion, seven hundred sixty-seven million, six hundred forty-six thousand, three hundred twenty-five".