221028205 has 8 divisors (see below), whose sum is σ = 265835232. Its totient is φ = 176421648.

The previous prime is 221028173. The next prime is 221028221. The reversal of 221028205 is 502820122.

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

It is a cyclic number.

It is not a de Polignac number, because 221028205 - 2⁵ = 221028173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 47679 + ... + 52108.

It is an arithmetic number, because the mean of its divisors is an integer number (33229404).

Almost surely, 2^221028205 is an apocalyptic number.

It is an amenable number.

221028205 is a deficient number, since it is larger than the sum of its proper divisors (44807027).

221028205 is an equidigital number, since it uses as much as digits as its factorization.

221028205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100235.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 221028205 is about 14867.0173538609. The cubic root of 221028205 is about 604.6200788449.

Adding to 221028205 its reverse (502820122), we get a palindrome (723848327).

The spelling of 221028205 in words is "two hundred twenty-one million, twenty-eight thousand, two hundred five".