644388768284 has 12 divisors (see below), whose sum is σ = 1127685999384. Its totient is φ = 322192768464.

The previous prime is 644388768269. The next prime is 644388768313. The reversal of 644388768284 is 482867883446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1209767 + ... + 1659009.

It is an arithmetic number, because the mean of its divisors is an integer number (93973833282).

Almost surely, 2^644388768284 is an apocalyptic number.

It is an amenable number.

644388768284 is a deficient number, since it is larger than the sum of its proper divisors (483297231100).

644388768284 is a wasteful number, since it uses less digits than its factorization.

644388768284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807844 (or 807842 counting only the distinct ones).

The product of its digits is 396361728, while the sum is 68.

The spelling of 644388768284 in words is "six hundred forty-four billion, three hundred eighty-eight million, seven hundred sixty-eight thousand, two hundred eighty-four".