228164221 has 4 divisors (see below), whose sum is σ = 233729244. Its totient is φ = 222599200.

The previous prime is 228164219. The next prime is 228164231. The reversal of 228164221 is 122461822.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 138180025 + 89984196 = 11755^2 + 9486^2 .

It is a cyclic number.

It is not a de Polignac number, because 228164221 - 2¹ = 228164219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 228164221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228164231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782450 + ... + 2782531.

It is an arithmetic number, because the mean of its divisors is an integer number (58432311).

Almost surely, 2^228164221 is an apocalyptic number.

It is an amenable number.

228164221 is a deficient number, since it is larger than the sum of its proper divisors (5565023).

228164221 is an equidigital number, since it uses as much as digits as its factorization.

228164221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5565022.

The product of its digits is 3072, while the sum is 28.

The square root of 228164221 is about 15105.1057924134. The cubic root of 228164221 is about 611.0581124641.

The spelling of 228164221 in words is "two hundred twenty-eight million, one hundred sixty-four thousand, two hundred twenty-one".