28009224 has 48 divisors (see below), whose sum is σ = 76911900. Its totient is φ = 9208512.

The previous prime is 28009199. The next prime is 28009231. The reversal of 28009224 is 42290082.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 25704900 + 2304324 = 5070^2 + 1518^2 .

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 11 ways as a sum of consecutive naturals, for example, 383652 + ... + 383724.

Almost surely, 2^28009224 is an apocalyptic number.

28009224 is a gapful number since it is divisible by the number (24) 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 28009224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38455950).

28009224 is an abundant number, since it is smaller than the sum of its proper divisors (48902676).

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

28009224 is an frugal number, since it uses more digits than its factorization.

28009224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 28009224 is about 5292.3741364344. The cubic root of 28009224 is about 303.6922381656.

The spelling of 28009224 in words is "twenty-eight million, nine thousand, two hundred twenty-four".