646443999990764 has 24 divisors (see below), whose sum is σ = 1132090708440720. Its totient is φ = 322989525676224.

The previous prime is 646443999990707. The next prime is 646443999990779. The reversal of 646443999990764 is 467099999344646.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 646443999990764.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187372367 + ... + 190791225.

It is an arithmetic number, because the mean of its divisors is an integer number (47170446185030).

Almost surely, 2^{646443999990764} is an apocalyptic number.

It is an amenable number.

646443999990764 is a deficient number, since it is larger than the sum of its proper divisors (485646708449956).

646443999990764 is a wasteful number, since it uses less digits than its factorization.

646443999990764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3452849 (or 3452847 counting only the distinct ones).

The product of its (nonzero) digits is 68568643584, while the sum is 89.

The spelling of 646443999990764 in words is "six hundred forty-six trillion, four hundred forty-three billion, nine hundred ninety-nine million, nine hundred ninety thousand, seven hundred sixty-four".