216099666 has 12 divisors (see below), whose sum is σ = 468215982. Its totient is φ = 72033216.

The previous prime is 216099641. The next prime is 216099679. The reversal of 216099666 is 666990612.

216099666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 112975641 + 103124025 = 10629^2 + 10155^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6002751 + ... + 6002786.

Almost surely, 2^216099666 is an apocalyptic number.

216099666 is an abundant number, since it is smaller than the sum of its proper divisors (252116316).

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

216099666 is a wasteful number, since it uses less digits than its factorization.

216099666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12005545 (or 12005542 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 216099666 is about 14700.3287718336. The cubic root of 216099666 is about 600.0922691433.

The spelling of 216099666 in words is "two hundred sixteen million, ninety-nine thousand, six hundred sixty-six".