64650217784 has 8 divisors (see below), whose sum is σ = 121219158360. Its totient is φ = 32325108888.

The previous prime is 64650217783. The next prime is 64650217787. The reversal of 64650217784 is 48771205646.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64650217783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4040638604 + ... + 4040638619.

It is an arithmetic number, because the mean of its divisors is an integer number (15152394795).

Almost surely, 2^64650217784 is an apocalyptic number.

It is an amenable number.

64650217784 is a deficient number, since it is larger than the sum of its proper divisors (56568940576).

64650217784 is a wasteful number, since it uses less digits than its factorization.

64650217784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8081277229 (or 8081277225 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 50.

The spelling of 64650217784 in words is "sixty-four billion, six hundred fifty million, two hundred seventeen thousand, seven hundred eighty-four".