28257432 has 128 divisors (see below), whose sum is σ = 86261760. Its totient is φ = 7539840.

The previous prime is 28257413. The next prime is 28257443. The reversal of 28257432 is 23475282.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 28257393 and 28257402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 274293 + ... + 274395.

It is an arithmetic number, because the mean of its divisors is an integer number (673920).

Almost surely, 2^28257432 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 28257432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43130880).

28257432 is an abundant number, since it is smaller than the sum of its proper divisors (58004328).

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

28257432 is a wasteful number, since it uses less digits than its factorization.

28257432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 209 counting only the distinct ones).

The product of its digits is 26880, while the sum is 33.

The square root of 28257432 is about 5315.7720041401. The cubic root of 28257432 is about 304.5866729470.

The spelling of 28257432 in words is "twenty-eight million, two hundred fifty-seven thousand, four hundred thirty-two".