228909 has 4 divisors (see below), whose sum is σ = 305216. Its totient is φ = 152604.

The previous prime is 228901. The next prime is 228911. The reversal of 228909 is 909822.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 228909 - 2³ = 228901 is a prime.

It is a D-number.

It is a Duffinian number.

228909 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228901) 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, 38149 + ... + 38154.

It is an arithmetic number, because the mean of its divisors is an integer number (76304).

2²²⁸⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

228909 is a deficient number, since it is larger than the sum of its proper divisors (76307).

228909 is an equidigital number, since it uses as much as digits as its factorization.

228909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76306.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 228909 is about 478.4443541312. Note that the first 3 decimals coincide. The cubic root of 228909 is about 61.1722267077.

The spelling of 228909 in words is "two hundred twenty-eight thousand, nine hundred nine".