228165121 has 4 divisors (see below), whose sum is σ = 228215812. Its totient is φ = 228114432.

The previous prime is 228165107. The next prime is 228165131. The reversal of 228165121 is 121561822.

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 80299521 + 147865600 = 8961^2 + 12160^2 .

It is a cyclic number.

It is not a de Polignac number, because 228165121 - 2⁵ = 228165089 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 228165121.

It is not an unprimeable number, because it can be changed into a prime (228165131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17856 + ... + 27841.

It is an arithmetic number, because the mean of its divisors is an integer number (57053953).

Almost surely, 2^228165121 is an apocalyptic number.

It is an amenable number.

228165121 is a deficient number, since it is larger than the sum of its proper divisors (50691).

228165121 is an equidigital number, since it uses as much as digits as its factorization.

228165121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50690.

The product of its digits is 1920, while the sum is 28.

The square root of 228165121 is about 15105.1355836351. The cubic root of 228165121 is about 611.0589159082.

The spelling of 228165121 in words is "two hundred twenty-eight million, one hundred sixty-five thousand, one hundred twenty-one".