228165221 has 8 divisors (see below), whose sum is σ = 238263360. Its totient is φ = 218081952.

The previous prime is 228165209. The next prime is 228165229. The reversal of 228165221 is 122561822.

228165221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 228165221 - 2¹⁰ = 228164197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228165229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37490 + ... + 43148.

It is an arithmetic number, because the mean of its divisors is an integer number (29782920).

Almost surely, 2^228165221 is an apocalyptic number.

It is an amenable number.

228165221 is a deficient number, since it is larger than the sum of its proper divisors (10098139).

228165221 is a wasteful number, since it uses less digits than its factorization.

228165221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7435.

The product of its digits is 3840, while the sum is 29.

The square root of 228165221 is about 15105.1388937672. The cubic root of 228165221 is about 611.0590051796.

The spelling of 228165221 in words is "two hundred twenty-eight million, one hundred sixty-five thousand, two hundred twenty-one".