643680217716 has 12 divisors (see below), whose sum is σ = 1501920508032. Its totient is φ = 214560072568.

The previous prime is 643680217711. The next prime is 643680217753. The reversal of 643680217716 is 617712086346.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643680217711) 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, 26820009060 + ... + 26820009083.

It is an arithmetic number, because the mean of its divisors is an integer number (125160042336).

Almost surely, 2^643680217716 is an apocalyptic number.

It is an amenable number.

643680217716 is an abundant number, since it is smaller than the sum of its proper divisors (858240290316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643680217716 is a wasteful number, since it uses less digits than its factorization.

643680217716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53640018150 (or 53640018148 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 51.

The spelling of 643680217716 in words is "six hundred forty-three billion, six hundred eighty million, two hundred seventeen thousand, seven hundred sixteen".