228728 has 8 divisors (see below), whose sum is σ = 428880. Its totient is φ = 114360.

The previous prime is 228713. The next prime is 228731. The reversal of 228728 is 827822.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 228728.

It is a congruent number.

It is an unprimeable number.

228728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14288 + ... + 14303.

It is an arithmetic number, because the mean of its divisors is an integer number (53610).

2²²⁸⁷²⁸ is an apocalyptic number.

It is an amenable number.

228728 is a deficient number, since it is larger than the sum of its proper divisors (200152).

228728 is a wasteful number, since it uses less digits than its factorization.

228728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28597 (or 28593 counting only the distinct ones).

The product of its digits is 3584, while the sum is 29.

The square root of 228728 is about 478.2551620213. The cubic root of 228728 is about 61.1560993491.

The spelling of 228728 in words is "two hundred twenty-eight thousand, seven hundred twenty-eight".