644727216676 has 12 divisors (see below), whose sum is σ = 1187655399280. Its totient is φ = 305397102600.

The previous prime is 644727216589. The next prime is 644727216677. The reversal of 644727216676 is 676612727446.

It is a hoax number, since the sum of its digits (58) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 644727216676.

It is not an unprimeable number, because it can be changed into a prime (644727216677) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4241626350 + ... + 4241626501.

Almost surely, 2^644727216676 is an apocalyptic number.

It is an amenable number.

644727216676 is a deficient number, since it is larger than the sum of its proper divisors (542928182604).

644727216676 is a wasteful number, since it uses less digits than its factorization.

644727216676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8483252874 (or 8483252872 counting only the distinct ones).

The product of its digits is 28449792, while the sum is 58.

The spelling of 644727216676 in words is "six hundred forty-four billion, seven hundred twenty-seven million, two hundred sixteen thousand, six hundred seventy-six".