28189240 has 16 divisors (see below), whose sum is σ = 63425880. Its totient is φ = 11275680.

The previous prime is 28189223. The next prime is 28189241. The reversal of 28189240 is 4298182.

It is a junction number, because it is equal to n+sod(n) for n = 28189196 and 28189205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28189241) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 352326 + ... + 352405.

Almost surely, 2^28189240 is an apocalyptic number.

28189240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28189240 is an abundant number, since it is smaller than the sum of its proper divisors (35236640).

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

28189240 is a wasteful number, since it uses less digits than its factorization.

28189240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704742 (or 704738 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 28189240 is about 5309.3540096701. The cubic root of 28189240 is about 304.3414618841.

The spelling of 28189240 in words is "twenty-eight million, one hundred eighty-nine thousand, two hundred forty".