216665166 has 16 divisors (see below), whose sum is σ = 441507024. Its totient is φ = 70858944.

The previous prime is 216665161. The next prime is 216665171. The reversal of 216665166 is 661566612.

It is an interprime number because it is at equal distance from previous prime (216665161) and next prime (216665171).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216665161) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 340351 + ... + 340986.

It is an arithmetic number, because the mean of its divisors is an integer number (27594189).

Almost surely, 2^216665166 is an apocalyptic number.

216665166 is an abundant number, since it is smaller than the sum of its proper divisors (224841858).

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

216665166 is a wasteful number, since it uses less digits than its factorization.

216665166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681395.

The product of its digits is 77760, while the sum is 39.

The square root of 216665166 is about 14719.5504686794. The cubic root of 216665166 is about 600.6152633139.

The spelling of 216665166 in words is "two hundred sixteen million, six hundred sixty-five thousand, one hundred sixty-six".