208910221 has 8 divisors (see below), whose sum is σ = 228339104. Its totient is φ = 189961200.

The previous prime is 208910203. The next prime is 208910227. The reversal of 208910221 is 122019802.

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

It is not a de Polignac number, because 208910221 - 2⁹ = 208909709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208910227) 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, 119055 + ... + 120796.

It is an arithmetic number, because the mean of its divisors is an integer number (28542388).

Almost surely, 2^208910221 is an apocalyptic number.

It is an amenable number.

208910221 is a deficient number, since it is larger than the sum of its proper divisors (19428883).

208910221 is a wasteful number, since it uses less digits than its factorization.

208910221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239931.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 208910221 is about 14453.7268896295. The cubic root of 208910221 is about 593.3622272327.

The spelling of 208910221 in words is "two hundred eight million, nine hundred ten thousand, two hundred twenty-one".