206668221 has 8 divisors (see below), whose sum is σ = 275624544. Its totient is φ = 137745360.

The previous prime is 206668213. The next prime is 206668229. The reversal of 206668221 is 122866602.

It is an interprime number because it is at equal distance from previous prime (206668213) and next prime (206668229).

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

It is not a de Polignac number, because 206668221 - 2³ = 206668213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206668229) 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, 17295 + ... + 26691.

It is an arithmetic number, because the mean of its divisors is an integer number (34453068).

Almost surely, 2^206668221 is an apocalyptic number.

It is an amenable number.

206668221 is a deficient number, since it is larger than the sum of its proper divisors (68956323).

206668221 is an equidigital number, since it uses as much as digits as its factorization.

206668221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16731.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 206668221 is about 14375.9598288253. The cubic root of 206668221 is about 591.2319570707.

The spelling of 206668221 in words is "two hundred six million, six hundred sixty-eight thousand, two hundred twenty-one".