28400256 has 96 divisors (see below), whose sum is σ = 82941300. Its totient is φ = 9326592.

The previous prime is 28400243. The next prime is 28400257. The reversal of 28400256 is 65200482.

28400256 is a `hidden beast` number, since 2 + 8 + 400 + 256 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 25160256 + 3240000 = 5016^2 + 1800^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (28400257) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 102390 + ... + 102666.

Almost surely, 2^28400256 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 28400256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41470650).

28400256 is an abundant number, since it is smaller than the sum of its proper divisors (54541044).

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

28400256 is a wasteful number, since it uses less digits than its factorization.

28400256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 28400256 is about 5329.1890565076. The cubic root of 28400256 is about 305.0989771039.

The spelling of 28400256 in words is "twenty-eight million, four hundred thousand, two hundred fifty-six".