28302228 has 18 divisors (see below), whose sum is σ = 71541834. Its totient is φ = 9434064.

The previous prime is 28302223. The next prime is 28302247. The reversal of 28302228 is 82220382.

It can be written as a sum of positive squares in only one way, i.e., 26193924 + 2108304 = 5118^2 + 1452^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×28302228² = 1602032219527968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28302221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 393051 + ... + 393122.

Almost surely, 2^28302228 is an apocalyptic number.

It is an amenable number.

28302228 is an abundant number, since it is smaller than the sum of its proper divisors (43239606).

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

28302228 is a wasteful number, since it uses less digits than its factorization.

28302228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786183 (or 786178 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28302228 is about 5319.9838345619. The cubic root of 28302228 is about 304.7475398999.

The spelling of 28302228 in words is "twenty-eight million, three hundred two thousand, two hundred twenty-eight".