216766656 has 84 divisors (see below), whose sum is σ = 624078000. Its totient is φ = 71935488.

The previous prime is 216766639. The next prime is 216766681. The reversal of 216766656 is 656667612.

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 11 ways as a sum of consecutive naturals, for example, 154245 + ... + 155643.

It is an arithmetic number, because the mean of its divisors is an integer number (7429500).

Almost surely, 2^216766656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216766656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312039000).

216766656 is an abundant number, since it is smaller than the sum of its proper divisors (407311344).

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

216766656 is a wasteful number, since it uses less digits than its factorization.

216766656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1686 (or 1673 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 216766656 is about 14722.9975208855. The cubic root of 216766656 is about 600.7090284677.

The spelling of 216766656 in words is "two hundred sixteen million, seven hundred sixty-six thousand, six hundred fifty-six".