25728 has 32 divisors (see below), whose sum is σ = 69360. Its totient is φ = 8448.

The previous prime is 25717. The next prime is 25733. The reversal of 25728 is 82752.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 8 and base 13.

It is a junction number, because it is equal to n+sod(n) for n = 25698 and 25707.

It is an unprimeable number.

25728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 351 + ... + 417.

2²⁵⁷²⁸ 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 25728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34680).

25728 is an abundant number, since it is smaller than the sum of its proper divisors (43632).

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

25728 is an equidigital number, since it uses as much as digits as its factorization.

25728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 72 counting only the distinct ones).

The product of its digits is 1120, while the sum is 24.

The square root of 25728 is about 160.3995012461. The cubic root of 25728 is about 29.5212907684.

Adding to 25728 its sum of digits (24), we get a palindrome (25752).

The spelling of 25728 in words is "twenty-five thousand, seven hundred twenty-eight".