28243728 has 200 divisors, whose sum is σ = 91224320. Its totient is φ = 8398080.

The previous prime is 28243723. The next prime is 28243777. The reversal of 28243728 is 82734282.

28243728 is a `hidden beast` number, since 282 + 4 + 372 + 8 = 666.

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 = 28243692 and 28243701.

It is not an unprimeable number, because it can be changed into a prime (28243723) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 763326 + ... + 763362.

Almost surely, 2^28243728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28243728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45612160).

28243728 is an abundant number, since it is smaller than the sum of its proper divisors (62980592).

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

28243728 is a wasteful number, since it uses less digits than its factorization.

28243728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 92 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 28243728 is about 5314.4828534863. The cubic root of 28243728 is about 304.5374265433.

The spelling of 28243728 in words is "twenty-eight million, two hundred forty-three thousand, seven hundred twenty-eight".