216603666 has 32 divisors (see below), whose sum is σ = 482328000. Its totient is φ = 72053280.

The previous prime is 216603643. The next prime is 216603671. The reversal of 216603666 is 666306612.

It is a self number, because there is not a number n which added to its sum of digits gives 216603666.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24285 + ... + 31983.

It is an arithmetic number, because the mean of its divisors is an integer number (15072750).

Almost surely, 2^216603666 is an apocalyptic number.

216603666 is an abundant number, since it is smaller than the sum of its proper divisors (265724334).

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

216603666 is a wasteful number, since it uses less digits than its factorization.

216603666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8231 (or 8225 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 216603666 is about 14717.4612620520. The cubic root of 216603666 is about 600.5584300985.

The spelling of 216603666 in words is "two hundred sixteen million, six hundred three thousand, six hundred sixty-six".