25439401728 has 432 divisors, whose sum is σ = 83121467520. Its totient is φ = 7712796672.

The previous prime is 25439401727. The next prime is 25439401747. The reversal of 25439401728 is 82710493452.

25439401728 is a `hidden beast` number, since 2 + 5 + 439 + 40 + 172 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25439401727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67122243 + ... + 67122621.

Almost surely, 2^25439401728 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 25439401728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41560733760).

25439401728 is an abundant number, since it is smaller than the sum of its proper divisors (57682065792).

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

25439401728 is an equidigital number, since it uses as much as digits as its factorization.

25439401728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506 (or 480 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 25439401728 in words is "twenty-five billion, four hundred thirty-nine million, four hundred one thousand, seven hundred twenty-eight".