25640928 has 96 divisors (see below), whose sum is σ = 76204800. Its totient is φ = 8385408.

The previous prime is 25640921. The next prime is 25640933. The reversal of 25640928 is 82904652.

It is a happy number.

25640928 is a `hidden beast` number, since 2 + 5 + 640 + 9 + 2 + 8 = 666.

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

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

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 25640892 and 25640901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25640921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50725 + ... + 51227.

It is an arithmetic number, because the mean of its divisors is an integer number (793800).

Almost surely, 2^25640928 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 25640928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38102400).

25640928 is an abundant number, since it is smaller than the sum of its proper divisors (50563872).

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

25640928 is a wasteful number, since it uses less digits than its factorization.

25640928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581 (or 567 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 25640928 is about 5063.6871941304. The cubic root of 25640928 is about 294.8794988071.

The spelling of 25640928 in words is "twenty-five million, six hundred forty thousand, nine hundred twenty-eight".