28424228 has 72 divisors (see below), whose sum is σ = 63174720. Its totient is φ = 10929600.

The previous prime is 28424219. The next prime is 28424233. The reversal of 28424228 is 82242482.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 28424194 and 28424203.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 281378 + ... + 281478.

Almost surely, 2^28424228 is an apocalyptic number.

28424228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28424228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31587360).

28424228 is an abundant number, since it is smaller than the sum of its proper divisors (34750492).

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

28424228 is a wasteful number, since it uses less digits than its factorization.

28424228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177 (or 152 counting only the distinct ones).

The product of its digits is 16384, while the sum is 32.

The square root of 28424228 is about 5331.4377047847. The cubic root of 28424228 is about 305.1847952955.

The spelling of 28424228 in words is "twenty-eight million, four hundred twenty-four thousand, two hundred twenty-eight".