28225728 has 42 divisors (see below), whose sum is σ = 80905604. Its totient is φ = 9408384.

The previous prime is 28225723. The next prime is 28225741. The reversal of 28225728 is 82752282.

28225728 is a `hidden beast` number, since 2 + 82 + 2 + 572 + 8 = 666.

It is a super-2 number, since 2×28225728² = 1593383442259968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28225692 and 28225701.

It is not an unprimeable number, because it can be changed into a prime (28225721) 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 5 ways as a sum of consecutive naturals, for example, 23926 + ... + 25077.

Almost surely, 2^28225728 is an apocalyptic number.

It is an amenable number.

28225728 is an abundant number, since it is smaller than the sum of its proper divisors (52679876).

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

28225728 is a wasteful number, since it uses less digits than its factorization.

28225728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49021 (or 49008 counting only the distinct ones).

The product of its digits is 35840, while the sum is 36.

The square root of 28225728 is about 5312.7890980162. The cubic root of 28225728 is about 304.4727179161.

The spelling of 28225728 in words is "twenty-eight million, two hundred twenty-five thousand, seven hundred twenty-eight".