66664512656 has 40 divisors (see below), whose sum is σ = 154032296064. Its totient is φ = 27328308480.

The previous prime is 66664512641. The next prime is 66664512751. The reversal of 66664512656 is 65621546666.

It is a junction number, because it is equal to n+sod(n) for n = 66664512598 and 66664512607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12936965 + ... + 12942116.

Almost surely, 2^66664512656 is an apocalyptic number.

It is an amenable number.

66664512656 is an abundant number, since it is smaller than the sum of its proper divisors (87367783408).

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

66664512656 is a wasteful number, since it uses less digits than its factorization.

66664512656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25879119 (or 25879113 counting only the distinct ones).

The product of its digits is 9331200, while the sum is 53.

The spelling of 66664512656 in words is "sixty-six billion, six hundred sixty-four million, five hundred twelve thousand, six hundred fifty-six".