216661055 has 16 divisors (see below), whose sum is σ = 283543680. Its totient is φ = 157966848.

The previous prime is 216661033. The next prime is 216661087. The reversal of 216661055 is 550166612.

It is not a de Polignac number, because 216661055 - 2²⁴ = 199883839 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15962 + ... + 26231.

It is an arithmetic number, because the mean of its divisors is an integer number (17721480).

Almost surely, 2^216661055 is an apocalyptic number.

216661055 is a deficient number, since it is larger than the sum of its proper divisors (66882625).

216661055 is a wasteful number, since it uses less digits than its factorization.

216661055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42290.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 216661055 is about 14719.4108238068. The cubic root of 216661055 is about 600.6114646030.

The spelling of 216661055 in words is "two hundred sixteen million, six hundred sixty-one thousand, fifty-five".