28308228 has 48 divisors (see below), whose sum is σ = 72065280. Its totient is φ = 8596224.

The previous prime is 28308223. The next prime is 28308251. The reversal of 28308228 is 82280382.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28308223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11176 + ... + 13472.

It is an arithmetic number, because the mean of its divisors is an integer number (1501360).

Almost surely, 2^28308228 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28308228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36032640).

28308228 is an abundant number, since it is smaller than the sum of its proper divisors (43757052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28308228 is a wasteful number, since it uses less digits than its factorization.

28308228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2396 (or 2394 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 28308228 is about 5320.5477161661. The cubic root of 28308228 is about 304.7690736114.

The spelling of 28308228 in words is "twenty-eight million, three hundred eight thousand, two hundred twenty-eight".