216660556 has 36 divisors (see below), whose sum is σ = 443126208. Its totient is φ = 92419488.

The previous prime is 216660533. The next prime is 216660557. The reversal of 216660556 is 655066612.

It is not an unprimeable number, because it can be changed into a prime (216660557) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41230 + ... + 46186.

Almost surely, 2^216660556 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 216660556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221563104).

216660556 is an abundant number, since it is smaller than the sum of its proper divisors (226465652).

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

216660556 is a wasteful number, since it uses less digits than its factorization.

216660556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5198 (or 5189 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 216660556 is about 14719.3938733903. The cubic root of 216660556 is about 600.6110035059.

The spelling of 216660556 in words is "two hundred sixteen million, six hundred sixty thousand, five hundred fifty-six".