66216656 has 20 divisors (see below), whose sum is σ = 139958304. Its totient is φ = 30098400.

The previous prime is 66216641. The next prime is 66216673. The reversal of 66216656 is 65661266.

66216656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187940 + ... + 188291.

Almost surely, 2^66216656 is an apocalyptic number.

It is an amenable number.

66216656 is an abundant number, since it is smaller than the sum of its proper divisors (73741648).

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

66216656 is a wasteful number, since it uses less digits than its factorization.

66216656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376250 (or 376244 counting only the distinct ones).

The product of its digits is 77760, while the sum is 38.

The square root of 66216656 is about 8137.3617346164. The cubic root of 66216656 is about 404.5657205396.

The spelling of 66216656 in words is "sixty-six million, two hundred sixteen thousand, six hundred fifty-six".