64666254816864 has 72 divisors (see below), whose sum is σ = 188864788170240. Its totient is φ = 20972839396608.

The previous prime is 64666254816853. The next prime is 64666254816883. The reversal of 64666254816864 is 46861845266646.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 64666254816792 and 64666254816801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3034254304 + ... + 3034275615.

It is an arithmetic number, because the mean of its divisors is an integer number (2623122057920).

Almost surely, 2^{64666254816864} is an apocalyptic number.

It is an amenable number.

64666254816864 is an abundant number, since it is smaller than the sum of its proper divisors (124198533353376).

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

64666254816864 is a wasteful number, since it uses less digits than its factorization.

64666254816864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6068529972 (or 6068529961 counting only the distinct ones).

The product of its digits is 1911029760, while the sum is 72.

The spelling of 64666254816864 in words is "sixty-four trillion, six hundred sixty-six billion, two hundred fifty-four million, eight hundred sixteen thousand, eight hundred sixty-four".