216660111 has 8 divisors (see below), whose sum is σ = 293192064. Its totient is φ = 142284120.

The previous prime is 216660091. The next prime is 216660181. The reversal of 216660111 is 111066612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216660111 - 2¹⁷ = 216529039 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216660181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 538755 + ... + 539156.

It is an arithmetic number, because the mean of its divisors is an integer number (36649008).

Almost surely, 2^216660111 is an apocalyptic number.

216660111 is a deficient number, since it is larger than the sum of its proper divisors (76531953).

216660111 is a wasteful number, since it uses less digits than its factorization.

216660111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077981.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 216660111 is about 14719.3787572710. The cubic root of 216660111 is about 600.6105923065.

It can be divided in two parts, 2166601 and 11, that added together give a palindrome (2166612).

The spelling of 216660111 in words is "two hundred sixteen million, six hundred sixty thousand, one hundred eleven".