228209 has 4 divisors (see below), whose sum is σ = 240240. Its totient is φ = 216180.

The previous prime is 228203. The next prime is 228211. The reversal of 228209 is 902822.

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, and also an emirpimes, since its reverse is a distinct semiprime: 902822 = 2 ⋅451411.

It is a cyclic number.

It is not a de Polignac number, because 228209 - 2¹² = 224113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (228203) 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, 5987 + ... + 6024.

It is an arithmetic number, because the mean of its divisors is an integer number (60060).

2²²⁸²⁰⁹ is an apocalyptic number.

It is an amenable number.

228209 is a deficient number, since it is larger than the sum of its proper divisors (12031).

228209 is a wasteful number, since it uses less digits than its factorization.

228209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12030.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 228209 is about 477.7122564892. The cubic root of 228209 is about 61.1098084816.

The spelling of 228209 in words is "two hundred twenty-eight thousand, two hundred nine".